I've linked this thread in the bug thread so hopefully we get more people answering the questions by a GURU on page 3.
Traveler is a likely culprit for this. So take that out AND DELETE YOUR CACHE FILES!!! It's not enough to just take the mods folder out.
Best is to rename your folder in documents to thesims3_EPBackup and let the game create a new one prior to installing the EP. You can put your stuff back folder by folder. Here's info what folder does what:
User Files Explained. You won't loose anything, it's still in the folder you made when you renamed.
Always test a new EP on a new game. This does not mean you can't return to your old savegame or that the progress there is lost, it's just to get a feeling what are bugs, what are mods or what is savegame corruption. You can even use your old savegame. Just back it up before you install the EP so you can go back if anything screws up.
Those who want to use CC and Mods need to educate themselves what they need to do when an new Patch/EP comes out. Updated does not mean free of errors in case of Mods. There are many bugs this game has - I'm the last person to deny that - but unless you remove the mods correctly that they are not present at all anymore, we can't say everything is an EA problem. If we do, everything gets just dismissed as mod bug (as the leaves staying in spring one) and never fixed.
Help by playing on a clean folder. Please.