Your suggestion helped me with a slightly different situation.
I have several partitions on each of two hard drives. On one of those partitions, I installed kde4. Been running and getting used to it, but kept having a strange occurrence: If certain partitions were opened and if I copied, pasted or edited files in those opened partitions, my empty desktop Trash Bin would sometimes unexpectedly become populated with numerous folders and files which I hadn't sent there. Fearful of deleting folders and files I hadn't sent to the Trash Bin, I'd close those partitions and then have to log out and back in, before the Trash Bin would return to it's empty state.
Taking your advise, I again opened those partitions and looked for hidden files. Sure enough, one partition had a hidden Trash Bin populated with those folders and files which kept finding their way into my desktop Trash Bin. Once I deleted that folder there's been no recurrence, solving the mystery. Apparently, I had deleted those folders/files many months ago and when backing up my /home to a separate partition inadvertently copied over a populated Trash Bin as well.