I have 2 drives, a dvdrom set as master, and a cdrw set as slave. I installed Ubuntu just fine with the dvdrom drive, but after rebooting for the first time, it doesn't work. If I leave a cd in when I boot (which is alot, I dual boot w/ XP) or put a cd in while in Ubuntu, it locks up the computer. I posted this in the forums on Ubuntu's site, but nobody could help me.
I'm relitively new with linux, but I'm trying to learn. So if you suggest anything, keep that in mind. Thanks.

Welcome to LQ! You need to be more specific. "My computer locks up", is a little to vague. What exactly happens, can you eject the cd from the drive, can you access your menus, does the drive spin up, etc.? Also, would be very useful to know what version of Ubuntu, kernel version and desktop environment you are using. The more information you can give the more likely someone here can help.
Regards,
TuxSurfer

From the useless information. Number one of all computer related problems like crashing is a cheapo power supply. I recommend replace the power supply with 100+ US dollar version. Brands that I recommend are Zalman, Enermax, Power & Cooling, Seasonic. I have a Seasonic S12-430 (430 watts) power supply. It fixed many problems. One of them was noise.

I can't remember if it spins up or not, but it basically just locks the computer, I can't do anything. I can eject the cd, but I still have to reboot to get it working again. When I boot with a cd, it loads to the black screen with the mouse cursor, but I can't move the mouse cursor.
As far as what version I'm running, it's 6.06 w/ gnome, but it did similar things when I installed 5.04 previously. It does the same thing before and after I updated.
I am pretty sure its not my power supply. I think mines an antec (came with the case) which isn't the best, but it shouldn't be the problem. Besides, it works fine in windows, so it's probably not a hardware issue.