I have this same problem - but with a USb attached samsung DLP - 500.
>I have a USR 5461 router/print server with a Brother
> HL-5140 connected to it via USB. It uses an internet port for printing
> (http://192.168.2.1:1631/printers/My_Printer). I have another XP computer and
> a laptop set up to print this way but Vista doesn't seem to recognize this
> kind of printing. Can someone point me in the right direction?

I have tried many times the fix below with no success.

>Add a printer
>Add a network, wireless or Bluetooth printer
>Not in the list
>Select a Shared printer by name
>enter the http stuff as the example states.
>http://192.168.2.1:1631/printers/My_Printer

>Alan Morris
>Windows Printing Team
>Search the Microsoft Knowledge Base here:
>http://support.microsoft.com/default.aspx?scid=fh;[ln];kbhowto -

I still get the cannot access error. I have tried disabling the windows firewall and NOD32 - no luck. Is there some other fix or work around? Help. CF