Disk Utility not seeing OWC External Drive(s)

[srexy]

I installed 2 Seagate sata drives in my OWC HDD enclosure and plugged it in via firewire 800 to my MBP. Initially the drives showed up as one volume due to the hardware raid 0 configured for the enclosure. I wanted the 2 drives to show up as separate volumes so I plugged them into my PC and opened up the XP disk utility which defaulted to some kind of "prepare disk for first use" window. I also ejected the HDD from the disk utility in OS-X. I'm not sure which of the above steps may have stuffed up my HDD but I can no longer see it in Disk Utility. Is there any sequence of steps to make my HDD visible again?