How should I set up my Episerver 5 sp3 web site so that an editor can not use illegal characters in file upload, for creating folders and uploading files?

Default in our web.config there is this code:

<virtualPath customFileSummary="~/FileSummary.config"
 illegalCharactersRegex="">

When I try to change the regex to the example in the sdk, it does not make any difference.

Editors can still create folders like "Månadsbild"
and upload files like "årsredovisning 2007.doc"

Best regards

Mats Bernerfalk