Packaging error in CS5.5

Hi there,

I'm trying to package an ID document that I upgraded from CS4 to CS5

and later to 5.5 on another machine. When packaging I get an error saying:

Cannot copy necessary linked file(s). The free diskspace is not an issue:

I have at least 480 Gb free space. Then I tried to make an idml and turn

that into a .indd doc and package that but I get the same error.

I'm sure it's something in the file as I have packaged larger documents

over the same network but those were native CS5.5 docs. Is there a way

to check/edit the document under the hood or something?

TIA.