HELP - profile viewing fatal errors

After users not being able to join or save profile edits for days now, I finally got that fixed. In typical Dolphin fashion, fix one major error and another pops up and nowwww....

When new users view their own profiles, they're getting this error message instead of their profiles:

Fatal error: Call to a member function set() on a non-object in /home/gsadmin/public_html/inc/utils.inc.php on line 578

They can go to profile edits from the edit link on the dashboard and/or the popup hover menu on member pages, however, edits won't save for them (they will for pre-existing members, though). It's the same incredibly frustrating "click save and nothing happens at all" issue as before, it's just limited to new members instead of all members.

Odd side note: I can edit the profile from the Admin menu and save changes even when the member can't edit their own profile.

Just curious. Did you install any mods around the same time this started that required editing core Dolphin files?

I updated from 7.0.8 to 7.0.9 several days before, but people were able to join and edit profiles after the upgrade. I also updated our php to PHP 5.3.13 the day before issues, but again people were able to join and edit after this update.

The only other change that was made was a user was deleted via admin>members.

I was able to get the join form to submit by deleting a module. However, without reinstalling that module suddenly the join form stopped working yet again.