since I haven't played the family since installing the new EP is it okay to assume they will all be unoccupied, because I think they probably are occupied unless they have been reset as usually happens with a new EP.
I missed that before... you're right, they'll probably be reset already. Question for the more awesome people, is there a scenario where a new EP installation could screw up a lot? Other than the saving-while-talking-on-a-cell-phone bug or the having-outdated-CC/hacks thing.
Speaking of CC: simsfreq, have you tried removing CC and loading the lot?
I still think the lot just got corrupted... it happens sometimes. I had one lot that kept registering there was a hot tub (for ACR), but there wasn't one on the lot. No amount of forcing errors, deleting things, etc. made any difference. Once they were moved to a new lot, all was well.