Samsung printer not duplexing

[Dave Stevens <geek@xxxxxxxxxxxx>]

Hi,

I recently upgrades FC3 -> FC5 x86_64 and now my Samsung ML-2150 won't duplex. 
Yum reports everything up to date. Ideas? Diagnostics I can do? I've tried 
the duplex test with no relevant info.

TIA,

Dave

ps,

[dave@localhost ~]$ uname -a
Linux localhost.localdomain 2.6.17-1.2187_FC5 #1 SMP Mon Sep 11 01:16:59 EDT 
2006 x86_64 x86_64 x86_64 GNU/Linux