sp_rename error when importing translated captions

I have been translating our application (based on the translate export) and when ready wanted to import (using translate>import) it into our application objects again. For the majority of the objects this worked OK, but for a small subset (~20 objects) I am getting the following error:

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The following SQL Server error or errors occurred when accessing the Company Information table:

297,"42000",[Microsoft][ODBC SQL Server Driver][SQL Server]The user does not have permission to perform this action.

SQL:
{CALL [sp_rename](?, ?, ?)}
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where of course the table mentioned will vary.
Searching for posts on sp_rename brought me to this one:
BUG Renaming fields fails at SQL “named instances”
It doesn't however help (whilst it's claiming that a similar issue should have been fixed in later NAV builds). Here on mibuso I did not succeed in finding any posts.
Anybody a clue on how to solve this?
One funny phenomenon was that with some objects this error occured the first time I tried to import, but when retrying (2nd, 3rd, ... time) it worked.

The system I am running on is:

Windows Server 2003 R2 SP2 NAV 2009 SP1

(haven't got more details on it at hand)