Windows system log contains code 7062 from SCM startup on QbikHk2K.
WinGate system log contains: "The ENS driver was not loaded. This may mean that it is missing or has been disabled. Press F1 for further details on possible causes and remedies."
GateKeeper Extended Networking properties panel contains only "General" tab with all controls disabled (except "..." button), status "not installed".
NAT doesn't work from LAN.
This problem is related with WG 6.5 only (both 6.5.1 and 6.5.2 were tried), 6.2.2 works normally. Re-installing 6.2.2 after 6.5.2 also works normally.
(Windows 2000 server SP4, all Microsoft updates, dedicated internet gate server (WinGate + Microsoft Exchange Server 5.5 SP4), no any configuration changes between 6.2.2->6.5.1->6.5.2->6.2.2 installations)
I don't know, it is important, but server computer has non-standard SMTP configuration (to run WinGate mail server and MS SMTP simultaneously), anyway, this configuration works with WG6.2.2 very stable.