I was having the same problem and I did a few things and it now works. I started off with a total clean install. I noticed my games were not all properly patched. So I decided to start from scratch. Loaded the game chose a household, loaded it, unpaused and CTD.
So I then did the DEP fix and added all of my Sims 3 exes to the list.
http://technet.microsoft.com/en-us/library/cc700810.aspx The area that is important is "
Enabling the DEP Exception List"
That for me fixed it. I was able to play. I readded my CC and hacks slowly. Items that have altered scripts crashed my game so I removed them. Example was Treeag's treasure box.
I then added back my saved sims, saves and Library. All of a sudden crashing to desktop. Finally I found it was my Library that was crashing me. I did have a lot of houses, sims, and sims with houses in there.
I just totally deleted and can play just fine now.
I am not sure if that will help you, but maybe this will help someone. I spent a lot of hours trying to figure it out.