Alright then! The problem has continued, but this time I noticed that the user had just changed their sig, so I did some testing.
I have determined the behavior that causes the bug.
1. A user uploads a pic smaller than my default, 50x50 for example.
2. The pic shows correctly, 50x50.
3. The user then goes to their home later and changes anything else in the profile, but leaves the pic alone. They hit submit.
4. The database resets the pic size to my default (65x75).
How do I keep editbasic.php from resetting the pic size if the user has not modified it?