I customized the IM user field to serve as a PIN for an on demand telephone messaging system.  In order to ensure that the users only use digits, we placed a Regex in it for validation: /^\d{4,7]$/

I put the regex in the textbox just as its shown above, no other characters, quotes or equal signs. I found no info on any other default format.  When we tested with the login role of a normal user it works as expected.  However, even with a valid 5 digit number in it, the validation error message will not stop showing up after clicking Update. Since it is a required field, one would expect the error to keep you on the user profile page.  However, I discovered (but my users won't) that it is possible to select a menu tab and go about their business. I can't figure out a reason for the regex to work and therefore be valid, but still display the error.  I've searched and googled looking for a lead but no ideas so far.  Anyone?