Windows 7 and direct printing to CUPS

[Andy]

Simple network of two new Windows PCs and one old Ubuntu server. The only LPT printer is connected to the server, and Windows clients are printing directly to CUPS: TCP-IP port is created, it has address like http://192.168.0.100:631/printers/Samsung-ML-1520, and the driver is MS Publisher Imagesetter.

When Windows XP was installed, everything was OK. But after upgrade to Windows 7 7600, printing fails, with message in logs (events-microsoft-printservice): "1241. The network address could not be used for the operation requested."

Pls help, how can I get Windows 7 printing? All preferences are just the same, as in XP. IPP client is installed. Protocol is RAW, Port 9100.