Hi Gideon,
I am out of town until next week. All I can suggest for now is to make a copy of the old ROI, then edit the copy and change Object_ID to self_idcode and Parent_ID to domain_parent_idcode and see if that would help (but I doubt it).
SUMA should work fine with old style ROIs. What I suspect is happening is that the name of the surfaces might have changed or perhaps something in the path of the surface names resulted in them having new idcodes. As a result, the idcode listed in the old ROI cannot be found.
You can also swap the entire Parent_ID line with the entire domain_parent_idcode line from the new ROIs. That should fix the problem.
Check back next week if none of these solutions work.
cheers,
ziad