adding hard drives to controller card in XP

Every time I try to add a hard drive in my multiboot
system, Windows XP goes nuts although 98 boots fine. I
have a Promise ATA card with one drive c: containing
windows 98 and numerous other partitions. The MB IDE has
a second hard drive D: which has the XP OS on one
partition. When i need to work on a third drive, no
matter where I put it, XP refuses to boot. I always need
to choose 98 which is inconvenient. Is there any easy way
around this without hand editing a bunch of substitute
boot files on the c: drive?