Ikebana DVD+R Drive won't Record

I have installed an Ikebana 4X DVD+R/+W drive in a Compaq Pressario (1.2 GHz Processor, 256 MB RAM) with XP PRO. I CAN get the drive to record in CD mode, but it fails in DVD+R Mode. I have Ridata +R discs (same mfr as Ikebana) but no go.
ALl connections check out.
Any ideas why this is not working???