I have a table with a fixed heading and body scrolling. None of the columns are aligned correctly.
Here is what I see in Google Chrome: 
This screenshot from this minimal HTML document I prepared:
<!DOCTYPE html> <html> <head> <style type="text/css"> html, body { margin: 0; padding: 0; font-family: Tahoma, Geneva, sans-serif; background-color: #888888; } .white_box { border: 1px solid black; background-color: white; } .round_corners { padding: 20px; -moz-border-radius: 10px; border-radius: 10px; } .shadow { -moz-box-shadow: 2px 2px 3px #000; -webkit-box-shadow: 2px 2px 3px #000; box-shadow: 2px 2px 3px #000; } .aligncenter { margin-left: auto; margin-right: auto; } #editpage { margin-top: 1em; margin-left: 1em; margin-right: 1em; } #updatesdisplay { width: 100%; border-collapse: collapse; } #updatesdisplay tbody { display: block; max-height: 500px; width: 100%; overflow-y: auto; } #updatesdisplay tr, #updatesdisplay thead { display: block; width: 100%; } #updatesdisplay th { font-weight: bold; font-size: 10pt; border: 1px solid #AAAAAA; padding: 3px; background: rgb(238,238,238); background: -moz-linear-gradient(top, rgba(238,238,238,1) 0%, rgba(196,196,196,1) 100%); background: -webkit-gradient(linear, left top, left bottom, color-stop(0%,rgba(238,238,238,1)), color-stop(100%,rgba(196,196,196,1))); background: -webkit-linear-gradient(top, rgba(238,238,238,1) 0%,rgba(196,196,196,1) 100%); background: -o-linear-gradient(top, rgba(238,238,238,1) 0%,rgba(196,196,196,1) 100%); background: -ms-linear-gradient(top, rgba(238,238,238,1) 0%,rgba(196,196,196,1) 100%); filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#eeeeee', endColorstr='#c4c4c4',GradientType=0 ); background: linear-gradient(top, rgba(238,238,238,1) 0%,rgba(196,196,196,1) 100%); } #updatesdisplay tbody tr:nth-child(even) { background-color: #CCCCCC; } #updatesdisplay tbody tr:hover { background-color: #DDDDDD; } #updatesdisplay tbody tr.selected { background-color: lightblue; } #updatesdisplay td { cursor: pointer; padding: 5px; border: 0; } .update-description { max-width: 150px; } </style> </head> <body> <div id="editpage" class="white_box shadow aligncenter round_corners"> <table id="updatesdisplay" cellpadding="0" cellspacing="0" border="0"> <thead> <tr> <th><input type="checkbox" id="select-all"></th> <th>Application Name</th> <th>Version</th> <th>Description</th> <th>Date Created</th> <th>Download URL</th> </tr> </thead> <tbody> <tr><td><input type="checkbox" name="sel1"></td><td class="update-appname">test</td><td class="update-version">0.5.0</td><td class="update-description">This is a simple test update designed to test the update system.</td><td class="update-created">2011-08-28 18:17:50</td><td class="update-download"><a href="http://localhost:8080/py/download?file=BeautifulSoup-3.1.0.1.tar.gz">http://sunjay.ca/test/download?file=BeautifulSoup-3.1.0.1.tar.gz</a></td></tr> <tr><td><input type="checkbox" name="sel2"></td><td class="update-appname">test</td><td class="update-version">0.5.1</td><td class="update-description">- Bug fixes</td><td class="update-created">2011-08-28 20:15:04</td><td class="update-download"><a href="http://sunjay.ca/download/test-0.5.1">http://sunjay.ca/download/test-0.5.1</a></td></tr> <tr><td><input type="checkbox" name="sel3"></td><td class="update-appname">test</td><td class="update-version">1.5.3</td><td class="update-description">- Bug fixes</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.5.3">http://www.sunjay.ca/up/test-1.5.3</a></td></tr> <tr><td><input type="checkbox" name="sel4"></td><td class="update-appname">test</td><td class="update-version">1.5.4</td><td class="update-description">- Bug fixes<br>- General Speedups</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.5.4">http://www.sunjay.ca/up/test-1.5.4</a></td></tr> <tr><td><input type="checkbox" name="sel5"></td><td class="update-appname">test</td><td class="update-version">1.5.5</td><td class="update-description">- Bug fixes</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.5.5">http://www.sunjay.ca/up/test-1.5.5</a></td></tr> <tr><td><input type="checkbox" name="sel6"></td><td class="update-appname">test</td><td class="update-version">1.5.6</td><td class="update-description">- Bug fixes<br>- General Speedups</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.5.6">http://www.sunjay.ca/up/test-1.5.6</a></td></tr> <tr><td><input type="checkbox" name="sel7"></td><td class="update-appname">test</td><td class="update-version">1.5.7</td><td class="update-description">- Bug fixes</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.5.7">http://www.sunjay.ca/up/test-1.5.7</a></td></tr> <tr><td><input type="checkbox" name="sel8"></td><td class="update-appname">test</td><td class="update-version">1.5.8</td><td class="update-description">- Bug fixes<br>- General Speedups</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.5.8">http://www.sunjay.ca/up/test-1.5.8</a></td></tr> <tr><td><input type="checkbox" name="sel9"></td><td class="update-appname">test</td><td class="update-version">1.5.9</td><td class="update-description">- Bug fixes</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.5.9">http://www.sunjay.ca/up/test-1.5.9</a></td></tr> <tr><td><input type="checkbox" name="sel10"></td><td class="update-appname">test</td><td class="update-version">1.6.0</td><td class="update-description">- Bug fixes<br>- General Speedups</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.6.0">http://www.sunjay.ca/up/test-1.6.0</a></td></tr> <tr><td><input type="checkbox" name="sel11"></td><td class="update-appname">test</td><td class="update-version">1.6.1</td><td class="update-description">- Bug fixes</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.6.1">http://www.sunjay.ca/up/test-1.6.1</a></td></tr> <tr><td><input type="checkbox" name="sel12"></td><td class="update-appname">test</td><td class="update-version">1.6.2</td><td class="update-description">- Bug fixes<br>- General Speedups</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.6.2">http://www.sunjay.ca/up/test-1.6.2</a></td></tr> <tr><td><input type="checkbox" name="sel13"></td><td class="update-appname">test</td><td class="update-version">1.6.3</td><td class="update-description">- Bug fixes</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.6.3">http://www.sunjay.ca/up/test-1.6.3</a></td></tr> <tr><td><input type="checkbox" name="sel14"></td><td class="update-appname">test</td><td class="update-version">1.6.4</td><td class="update-description">- Bug fixes<br>- General Speedups</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.6.4">http://www.sunjay.ca/up/test-1.6.4</a></td></tr> <tr><td><input type="checkbox" name="sel15"></td><td class="update-appname">test</td><td class="update-version">1.6.5</td><td class="update-description">- Bug fixes</td><td class="update-created">2011-08-28 21:38:23</td><td class="update-download"><a href="http://www.sunjay.ca/up/test-1.6.5">http://www.sunjay.ca/up/test-1.6.5</a></td></tr> </tbody> </table> </div> </body> </html>
Please help me figure out what is wrong. Thanks!