I had this problem as well. Here's the workaround until CUPS gets updated...
This problem is documented in bug 482836. It affects Windows Vista 64 and Windows 7 64-bit clients trying to connect to a Ubuntu 9.10 CUPS-networked printer. Error messages in Windows are vague and uninformative; I received error code 0x0000000d.
The solution is to bind a network printer to LPT1 using this command from Windows. ie:
You may have to run command prompt (cmd.exe) with administrator privileges. The persistent switch will allow this setting to be retained after reboot.
net use lpt1 \\UbuntuHost\MyPrinter /persistent:yes
Then map a local printer from Windows to LPT1. Voila!
Thanks to the Ubuntu community for support over the years.