When I like to export/download the quiz results in Excel- or text-format, I recieve a page with a lot of unstructured signs and letters on it (with IE 7 and Firefox 2.0). There is the same problem in the gradebook. The export is not working as well.

In the debug-mode there is an error-message: "Cannot modify header information - headers already sent by (output started at moodle/question/type/regexp/lang/en_utf8/qtype_regexp.php:25) in /moodle/lib/filelib.php on line 290".

It seems that there is a problem with the installed question-type regexp?
After removing the blank lines in the qtype_regexp.php it worked.