I think this might have happened to me as well.  I purchased 500 BTC into wallet ID 1Jf48wufcDpPQ2EEgX1jUULuTHVzDhqBSF which I left unencrypted within the generic bitcoin client wallet on my desktop at home.  I tried to launch the bitcoin app this weekend but it did not run.  I am not a very tech savvy person so I am not sure if it is somewhere on my computer and I just can't find it, or if it was stolen.

Any advice appreciated.  I tried to provide details to see if anyone has any suggestions.  Thanks and sorry for hijacking, but I figure there are more than 2 dummies that ened help