VMDirectPath of an Adaptec 39160 on an HP DL380 G5

Hi,

I Install ESX4 on an HP DL380 G5 with an Adaptec 39160, hoping to use it for a tape library. Unfortunately ESX informed that the host does not support VMDirectPath, although the machine CD-ROM does appear as as a possible SCSI target.  Anyone has any experience with this machine and the possibility of VMDirectPath on it?

Thanks

Gil