This might be a copy and paste problem, but you need an end quote in <p style=... > , which should help. Another option is to set text-align: center in the actual <div> so that you align the text inside the div. Both of them worked in IE 9 - what version of IE do you use to prevent it from working?
<html> <head> <title>test</title> </head> <body> <div style="position: relative"> <p style="position: fixed; bottom: 0; width:100%; text-align: center"> bla bla</p> </div> </body> </html>
OR
<html> <head> <title>test</title> </head> <body> <div style="position: relative; text-align: center"> <p style="position: fixed; bottom: 0; width:100%;"> bla bla</p> </div> </body> </html>
source share