DVD writer problems

I have been burning home movies to DVD using Roxio, both with my HP DVD writer and my external Plextor for a year without any problems. Recently I developed several problems. when using the roxio DVD creater often my computor will not recognize a DVD in either my HP DVD drive or my Plextor drive and when it does and I try to burn the operation halts midway because of errors occuring while writing. I downloaded Adobe's premiere elements to see if the problem was Roxio, But I have the same problem with Adobe premiere. Can anyone help me trouble shoot this problem.

Just wanted to add that I get this error message drive not accessible because of an I/O device error.

Was reading something about the DMA mode vs PIO so I went into my comp's Device Mgr and checked the status of the IDE ATA/Atapi controllers and all the primary and secondary settings are set to DMA. Hope that helps to help me trouble shoot this problem.

today I just noticed that my DVD drive was not able to recognize a home made DVD that I made using that DVD drive. Can anyone help me trouble shoot this problem?

Thanks Evan

Computor specs:

Computer Name: HP Pavilion MCE

Operating System: Windows XP
Ver. - (2002)
Computer Make: Pavillion
Model - (M7300e)
Processor: AMD Athlon 64X2 Dual Core
Processor Speed: 1.99 GHz.
Memory: 2.00 GB.
Hard Drive: 300 GB.
Screen Resolution: 1280 by 1024
Web Browser: Mozilla firefox

* Operating System was preinstalled.
* This computer is a Desktop or Tower.

* I connect to the Internet using a High Speed connection.