One of my users has reported the following error while trying to change his signature:

"It does not appear that this was submitted from the proper form.
Please use your back button to return to the previous page."

I haven't checked to see if the editbasic.tmpl form is being validated. On a side note: I can change my signature without any problems (but I have admin rights).

This problem only happens when using FireFox -IE works fine.