Some docs not checking in

Every once in a while in a large assembly, a part that I knowIhave altered will show up in the vault check in dialog with agreenarrow (i.e. it's newer than the vault copy) but willnotautomatically check in with the assembly.  Is there areasonfor this? I have taken to carefully running 'My PDMworkscleanup'on my working copy folder every day just to make sure thatnothingis deleted if it didn't check in with the assembly. This getsconfusing when trying to maintain an 'asbuilt'.SolidworksWorkgroup Pdm