My sims panel pic turns into the wrong person when i add a new sim to household

if I understand correctly you are using the cheat to move your sims in together. ? You can try not using the cheat and just having them get married and they will get an option to move in together, you can go to city hall if you need to change their names. Try deleting your cashe package files. It cleans the game without deleting anything in the game and the game will regnerate new files when you delte them http://simswiki.info/wiki.php?title=Game_Help:Sims_3_Delete_Cache_Files

Would this be it? http://sims3.crinrict.com/en/2011/10/bug-multi-selected-portraits.html

PS I dont have pets installed and that pic issue has happened to me so I dont know if pets is your cause or not so try methods above and see if clearing your cashe works.

I've tried all the options and then tried to cheat to add to active household and it still happens.

This is exactly my problem. Should I restart the game after I save it as a different name? I don't want to save my game and then never have the problem fixed.

try using "save as" and renaming the file instead of regular save. using regular save overwrites your old game and could be come corrupt. "Save as" gives you a new save rather than overwright the old save.  Try cleaning out your cashe files. Its possible you have a corrupt save. Check your saves folder in documents, Electronic Arts folder, to the sims 3 folder, to the saves folder. If you have any saves with "Bad " on the end of those get rid of them. In general if you ever get an error while trying to save it will give you a save with "Bad" on the end of it.

if none of this has worked, possibly this will work: http://simswiki.info/wiki.php?title=Game_Help:Sims_3_Delete_Cache_Files

This is completely safe, i just did it to try and fix my game.