I have a a QC user having problems logging into QC 9.1. He is using QC Explorer to access QC, as he has IE 8 on his machine.

The first time he logs in, it is OK, but he then logs out and closes QC Explorer and starts a new session, the login hangs at 'Get Visable Domains'. He needs to keep uninstalling and reinstalling QC Explorer each time.

I've tried reinstalling the QC client and QC Explorer, have recreated his user, but it's still the same. We tried his windows and QC login on a different machine and it is OK, so it's specific to his machine.

Any ideas what could be causing this or what else to check?