Outlook 2010 and Meeting Resources not showing meetings

[Hfnet]

We have a few users on an Exchange 2010 / Office 2010 setup that cannot see meeting requests in the resource they have booked (it is in their calendar). They get the confirmation email and we can see it in OWA, and if they look in a non-cached version of Outlook they see it, then when they revert to a cached mode, the appointment appears in the meeting room.

I have asked them to run outlook /cleanfreebusy, but has anyone else any ideas?

Thanks.