mine does that too! it drives me bananas. does it happen with every one of your houses? only some of my houses do it. i built this big beautiful house, fully furnished. and moved some sims in and within 2 minutes the application crashed. I moved the sims out, had to delete all the furniture, but at least i can keep the house. I moved new sims into it, havent gotten to furnish it yet, but it hasn't crashed when i let the sims run around in it for 20 minutes to test it.
unfortunatly the best fix i have found for it is to save very often, and run a timer to see when it crashes. for a while, one house would crash every 5 minutes, and then i would keep playing it and it would go longer and longer without crashing. unfortunatly not a great fix, but it gives me an idea of when to save.
do you have any custom content on your game? i have tons, and i bet that is what my problem is. i refuse to delete all of it, so i just deal with the crashing. try moving your houses around in the neighborhood, and build some new ones. i know it sucks, but the best thing i can offer is uninstall everything and basically start over. my boyfriend is a computer genius and thats what he tells me to do, but i don't want to!!!
and you deleted EVERYTHING? did you backup the games, uninstalled them, installed them again, and loaded the backups? that probably won't work. don't use backups, and try starting the game over completly. if that doesnt work, i suggest calling the EA help line.