WRITER ERROR [UNIT ATTENTION (Power on, reset, or BUS Device reset ocurred)]

Hey guys, I've been burning DVD's for a while now but never really had any trouble until recently, so in terms of fixing things I'm definitely a newbie so I followed the advice at the top of the thread due to the fact that i was getting the same I/O Error message as bobesox. I just wasted the last Verbatim DVD+R I had so I wasn't able to check the disc, but the DVD identifier produced this:

[18:48:28] DVD+R/+RW Medium Detected. Starting Identification...
[18:48:28] ** Initiating ADIP Retrieval Method 1 (Original ADIP)
[18:48:28] ADIP Read M1 Failed : Illegal request - Invalid field in CDB [05/24/00]
[18:48:28] ADIP Read Method 1 Not Supported ; A Firmware Upgrade Is Recommended
[18:48:28] ** Initiating ADIP Retrieval Method 2 (Copy Of ADIP)
[18:48:28] ADIP Read Method 2 Completed Without Errors
[18:48:28] Disc Identification Completed Successfully

I've received an error code regarding firmware before, but I have no idea what this means. It seems kind of odd the the first 25 Verbatims burned with only 1 or 2 errors but of the last 25 in the pack only 5 or 6 worked. I'd appreciate any help you guys could give me, I'm not sure if the problem lies in the drive or the media