A critical issue on my bootcamp disk. Please help.

I have an extremely weird issue on my bootcamp disk. I try to boot my bootcamp disk by choosing start up disk in system preferences. Nonetheless, the bootcamp disk is gone. I can’t see the bootcamp disk in the list. I can choose only OSX or network startup. So, I recycle the power and hold option key to start up. This time, I can choose “Windows” and boot the Windows without any problem. Then, I go to bootcamp tool and surprisingly, both OSX and Windows are in the list. I choose the OSX and hope that bootcamp disk will show up in the list. Nonetheless, it didn’t show up when I boot from OSX. In addition, I also tried to boot up from OSX CD. I still can see both OSX and Windows in that list. But, I encounter the same situation. Bootcamp is still missing in that list of start up disks. Does anyone have this problem before? Any idea is appreciated. Thank you.

 

Thank you for the advice. I am running XP SP3 on bootcamp 2.1. I've used this bootcamp disk without any problem for more than a year. The only thing I've done before this weird thing is to reset my PRAM. After that, bootcamp disappeared.
In addition, I also tried sevdral things. I tried to use utility tool to repair the bootcamp disk. I also tried to use "chkdsk c:/r" in Windows. None of these do the trick.