Profile field categories containing slash characters impossible to edit under "My account"

Issue Summary

The profiles module allows administrators to create custom profile fields, which are grouped into categories that the administrator specifies. These category names are allowed to contain slashes, such as "this/that example".

Later, when users attempt to edit information under My Account -> Edit, categories containing slash characters appear empty even though they should display editable profile fields. I suspect that the problem is that the slash character is being processed as part of the URL:

http:// somedomain/user/2/edit/this/that+example (clean URLs)
http:// somedomain/?q=user/2/edit/this/that+example

Removing the slash characters from affected categories under User Management -> Profiles seems to resolve the problem.

Ideally, slash characters could be included in category names. At the very least, admins should be prevented from entering slash characters when typing a category name.