I have been working on a layered PSD file putting together a website visual for a few weeks. Yesterday I went to save a copy of the document and in that process the file went a bit weird and some text changed colour and 5 layers had a portion of them deleted (all photos in the header area, like in the attached image). It's happened twice since yesterday, but can't seem to recreate it.
Sounds a bit like an issue that has been discussed at length, see post 182 in the following thread for example.
I didn’t follow that thread very closely but I think the issue was not resolved (despite several Adobe employees trying to track the problem down) and some people who had it could not reproduce it reliably.