Some content has disappeared from my game!

Since I've installed FT I've noticed that a few of my custom objects no longer work. They appear in the catalogue but when I click on them I can't actually put them into the sims houses. I thought this might be a GUID problem. Is that likely to be what it is or is it just that the expansion pack has broken a random selection of objects? If it is the GUIDs is there anything I can do about it?

Also I have noticed that a pair of Maxis trousers from the base game no longer show up. These were working fine before I installed FT and I was wondering if this was something EA did to break them. If someone could check these trousers in their game I'd be grateful. It's a pair of adult male trousers, they are the sort of tan colour with creases down the front and come with either white or brown sneakers (possibly other colours too). It's the ones with the brown shoes that don't seem to work; if I dress my sim in them he gets a pair of red trousers instead.