Chief Delphi - Finding a deleted part reference

I was recently changing some things with the CAD model of our robot. I deleted stuff and all was going fine. Then after a few days i started to get messages saying that a part file link was broken and needed to be resolved. The only problem is inventor won't let me resolve the link with the missing part file, new part files with the same name, or any other part file. I have gone though the CAD model and can't find the reference for this file. The strangest thing is when i open the sub assembly that this file is in i don't get the resolve the link message. But when i open the overall assembly i do. Can someone help me out?