Hi Evets,
I think that this is due to windows caching the DNS record for the GTC site.
To (hopefully) fix the problem:
XP:
* Go to Start, Run and enter "cmd"
* Type "ipconfig /flushdns" into the command prompt.
* Press Enter. You will be informed that your DNS cache has been cleared.
Vista:
* Go here:
www.petri.com/vista_command_prompt and follow the steps marked "Creating an Administrator Session Shortcut"
* Type "ipconfig /flushdns" into the command prompt.
* Press Enter. You will be informed that your DNS cache has been cleared.
An easier way might be to reboot your machine.