Easybcd on Win7 RC1 - problem ?

I have Win7 RC1 and have a problem I've posted regarding a blank screen when trying to boot into XP in a multi boot system (Xp Pro-Vista-Win7RC1-Ubuntu)
I have tried easybcd Beta 78 replacing the xp entry and using autoconfigure - also having given the primary system boot drive a drive letter but I get a blank screen if I select XP. The others all work fine. If I go to Vista and delete the Win7 partition, then reboot and select XP it comes up normally.

Is it possible that Win7 RC1 has a problem in this area ?