New environment, Access 2010 compact and repair of any .accdb file suddenly fails

Hi

I've been migrated a few days ago from one version of Citrix/Terminal servers on Windows Server 2003/Access 2007 to a newer version of Citrix/Terminal servers on Windows Server 2008 R2/Access 2010. The file system remained the same, i.e. I find my files at the same place as before on the same remote drives with the same names. I have about 20 Access front-ends which I develop and maintain.

At the beginning, I had no problems, but now I'm getting more and more often errors when I want to compact/repair my apps. I have certainly compacted/repaired them thousands of time under Access 2007 (I always do after every change I make), but now I get the ominous "Could not use <.accdb file name>; file already in use" when I try to compact/repair ! Which is ludicrous, because of course the file is in use, it's being repaired by you Access, man !

Worse, if I try to compact/repair again, I again get an error message telling me that the app could not be replaced, and the (compacted) app is being renamed to "Database.mdb", so I have to open it in "shift mode", and save it as .accdb / 2007 format. This is driving me nuts. I've started to NOT compact/repair for fear of the whole procedure.

Any idea what could cause this problem ?