I've got 6.5 and very slow printing as well.  I've tried installing as local printer and changing port to network address, but it's no faster.
Here's my configuration:
SME 6.5
WinXP Home
Epson740 on USB1
WinXP Epson Esc/P driver
I used 6.01 for quite some time and just upgraded to 6.5 (fresh install and dumped files back into ibays/user folders).  With 6.01, I set up printers with Cups and that seemed to work fine.  What exactly is 6.5 using for printing now (ie. Cups, lpr, etc...).  I can't seem to access cups to try manually setting up a printer like I had done previously with 6.01.
Any further suggestions?