BTW: I learnt the hard way about backing up. When I first got the game I was like a fraudster with a visa card, I DOWNLOADED EVERYTHING !!!
Dude, if it wasn't made by EAxis, don't pay for it. Paysites are bad, mmkay? Clicky the linky in the top right corner. Also, note that the constant capitalization makes you look like a raving idiot.
As far as SimPE goes, changing a sim's personality won't bork your game. I suspect you did something else, too, and/or were using an inappropriate version of the program for the game you have. Not a huge criticism...there's a lot of options there, and for a new user you can get a little too excited and want to try everything out.