> I also read that NOD32 antivirus may be causing the problem. This PC has
> this antivirus. So I deactivated it but the problem continuous.

Deactivation does nothing. IIRC, you need to add fbserver.exe to the INET
exclusion list. I don't remember if it helps really. If not - you need to deinstall
NOD32 completely. Or don't use FB SS. Or don't use TCP\IP connections.

Regards,
Vlad