Ubuntu/XP Dual Boot won't load XP

Hey guys,
So I recently partitioned my hard drive using partitionmagic, and split off a bit to install Ubuntu. I installed it, no problem, everything was looking fine and Ubuntu worked like a charm, up until I tried to boot back into XP. I chose XP from the OS options list, and it loads the windows logo with the bar underneath, and then it looks like it's trying to run a chkdsk or something, but says 'autochk not found', and then goes to a blue screen. I've tried going into recovery console and running chkdsk, but it seems to be taking an inordinate amount of time to run (almost locking up around 50-53%). Any ideas as to what's going on?