I have this problem... I started out with a working version of XP, when I got my vista upgrade in the mail I decided to pop in another drive and install a dual boot system vista installed great but thats where the fun system would only boot to vista when the install cd was in the drive and to xp when no bootable disc was in the drive.I rearanged the drive cables so I could boot to vist straight off but that still didn't solve my problem so I have tried using easy bcd to set up my boot luck . can any body help please.
Add a Windows XP entry in EasyBCD, then modify your boot.ini to point to the right partition numbers.
In EasyBCD go to the add/remove screen -> linux and look at the list of drives - find the XP one.
It should be labeled as drive X partition Y

Boot.ini should be disk(x)rdisk(0)partition(y+1)