I see this morning that a new driver was posted on the DDPAK to support the IOMEGA Parallel port drives, old Zip, Zip Plus, and Zip 250!!!
This driver is an ADD style driver and completely replaces the IOMEGA supplied OAD.SYS!!
(and it works!!!, altho listed as BETA in the readme)
http://service.software.ibm.com/os2ddpak/html/
in the Removable Disks section
Sam
Source: OS2VOICE