ok, this can mean 2 things:
1- You had duplicate media’s on 3.5 (meaning: the same media was part of 2 different modules/solutions) and now it cannot access the one it’s linked to (due to the module strucure) while you access the other one located in the module/solution where you expect it.
2- something is going wrong in the export/import.
To check the first: Open the Navigator view and locate the .frm file that has the -unresolved- property on it. Open it as a text file and locate the property that is -unresolved-. In the .frm file it should have a long identifier (UUID) as value. Then search throughout your entire workspace (Control-H) for that UUID to see if it is used anywhere as a unique identifier for a media. If it is, look at the module/solution it is in.
If the above is not clear, it’s best to create a support request in our support system and attach a zipped version of your workspace.
Paul