Access 2010 issues opening Access 2000-2007 database

I recently upgrades 3 computers to recent HP notebooks, Windows 7 and Office 2010.

However, the company works with several (old) access databases (varying from 2 to 60Mb in size).

Opening these on old machines (XP/Vista, Office 2007) causes no problem. However, on the Win7 notebooks with Office 2010 Access basically crashes ("not responding") when opening. When leaving Access open for a while (anything between 15m to 1h3m0) will eventually open the databases, and the users are able to work in it. But as you might guess, that's just a tiny bit too slow.

CPU wise, when opening the database, 2 of the 4 cores are working. One around 80%, the other at 20%. Rest is idle. No high memory usage either.

The Access databases are on a network share, but making a local copy (on the Desktop for example) didn't change anything.

I installed all available updates.

Edit: problem happens when opening a query or table (not when double clicking/opening the file in itself).