Sounds to me like it's a problem from day one with the house! Sucks, I know.
Just FYI, not code or anything, but if GE loadcenter, then GE breakers, Square D, Square D. Reason being if the house burns, homeowners insurance will NOT pay in most cases. Code or not! Word to the wise.
It's quite possible just replacing the breakers with GE breakers you could be fine, but why chance it?
Post a pic of your panel. I'm off this weekend and in DIRE need of some r and r. Wouldn't be the first time I've pulled a meter hot. Got jumper cables? We can get you hooked up with a good Square D panel, or better yet, a 400 amp service if you're up to the coin for a $700 panel vs a $150 panel.
Ray