I've tried both upgrading and a fresh install and RH v6.1 doesn't see my parallel port (/dev/lp0). I have an AMD K6-2 450MHz on an ASUS P5A-B Mothermoard w 128MB RAM. 8GB disk, 2 HP 9100 re-writable CDs. a Hi-Val 3D 16 Souund card, an Adaptec 2906 SCSI, and a Phoebe 10/100 Ethernet card. RH v5.2 saw it.
This is a bug in the installer. Add the line alias parport_lowlevel parport_pc to your /etc/conf.modules manually for now.
Fixed in the 6.2 installer