Partition showing?

i have the main drive partitioned, i cant even open bootcamp to remove or alter the partition, my main problem is that when i turn the comp on and hold the option key down it should give me the option of choosing between the two partitions(it used to) but now it doesnt.

in os x make windows the start up disk (im guessing it's windows on the other partition). reboot and it should boot into windows. Have your windows xp cd in the drive and while restarting it should boot into the xp cd. choose to install xp or whatever and u should get to the screen with all the partitions on it. just delete the partition with windows. exit out and restart back into Mac and re run bootcamp and reinstall windows. Thats all I can think that will work so use as a last resort I guess, surely there is an easier way to fix it, i'm just giving an option.

OR, an annoying way to get around it is just switch the start up disk to other partition every time u want to boot into it and then just restart.