Windows Print Servers, 32 & 64 bit drivers

I had always thought that Windows print servers (32 or 64 bit) could host the drivers for other bit-level OSes. I have a 32-bit print server that refuses to host the 64-bit drivers, and I’ve just created a 64-bit print server that I discover won’t host the 32-bit drivers.

These are both W2K3 R2 servers. I install the 64-bit driver on the 64-bit print server, enable sharing and then tried to add the 32-bit driver. When I navigate to the ‘inf’ file and try to load it I get, “The specified location does not contain the driver for the requested processor architecture.” Yet, that 32-bit driver is in use on the 32-bit server, so I know it works.

What am I doing wrong?