Plextor Cd-RW

We have just received new 40x and 48x plextor CDRW’s to install and the first few machines(P 1.4, Asus mb, win2K) were unable to read discs. Bios picks up drives ok, EZ-Cd creator gives error ‘no CD-R present’ when you try a copy disc.
Older 24x drives work fine. UDMA is enabled in Bios, plextor site says Win2K supplies drivers, none are available for download for 2000, any ideas?