Maybe this is what vfwiffo was trying to say...
If this for some reason doesn't solve your issue then I refer back to what I originally posted as it was how I resolved the same described crashing problems a while back.
Indeed, that is what I was referring to. Thanks for reposting. That was posted many times, by myself and others.
I am not entirely sure the PAC problem is exactly as you described; I heard of people having this issue who I believe had the pet in 1st slot. I know of at least one person solved this by taking PAC off, restarting toon, quitting (to write clean toon-specific savevariables.lua) and then reinstalling PAC. I don't know if this is reliable fix or not; just removing the file and letting system recreate it works every time I recommended it. There is next to nothing in that file of any value - most setting are saved in general savevariables.lua, not the toon-specific one.