Restart Problem

[MBrolling]

I couldn't find a similar issue through searching, so sorry if this is a repost. I am not sure if this is due to the 10.5.6 update yesterday, as I really have not restarted my computer in about a week. But now when I restart, instead of going into OSX, it boots up in windows xp. So I thought, ok I will just delete that partition. So I boot up in OSX (through option) then delete the windows partition through bootcamp and restart my computer, and now it gives me that black screen and says to insert cd and press any key (presumably to load xp). Could deleting the partition through bootcamp not thoroughly done it? And I also updated to 10.5.6, but I am really not sure if that is what caused the bootup problems, because when mine didnt work the first time (had the hanging problem at install and had to manually shutdown,) it still booted up in xp.