Ok, I hope some can please help!

I have an internal Lite-On DVD-RW writer (451s, I believe). I have written several CD's and DVD's with no problems in the past, but suddenly, now I am having issues. I keep ending up with coasters every time I try to burn a DVD out of DVD Architect 2.0 or any other application. Roxio Easy Creator doesn't even see the drive. BUT, I can play DVD's and burn CD-Rs with no problem. It is just when I try to write a DVD I have a problem. This is very strange to me!!!! I have checked to make sure I am using the right speed DVD's etc. and all that is fine. So, what am I doing wrong???!!!!

I am running Windows 2K, 2 ghz Athlon and 1 gig of RAM. Pls help if you can think of a solution!!!

OutLan