This happens for the same reason that mixing logical AND and OR always fails.
What you say here is valid (in pseudo-code):
If (
File Not Named '*.jpg' AND
Path Matches './bookshop/mediaimg' AND
Prone OR
Path Matches '*/CVS*' AND
Prune OR
Path Matches './files' AND
Prune OR
Path Matches './images/cms' AND
Prune OR
Path Matches './internal' AND
Prune OR
Path Matches './limesurvey171plus_build5638' AND
Prune OR
Path Matches './gallery2' AND
Prune OR
Print
)
print true, , , , AND , OR . , , , .