I will apologize in advance. I don't know much about DVD-RW drives, other than they usually just work. I have only ever encountered problems with media for various purposes. I have a Samsung (I think) TSST- S223F drive that when initially installed was giving me all kinds of problems. I have had it between 4-6 months and have only burned maybe 200-300 projects with it. It had trouble reading discs, initially, especially data DVD's. It also had extremely slow write speeds, like under 2x.
I updated the firmware a few months ago and that seemed to solve all my problems. Burn speeds typically started somewhere around 10x and peaked at 17x. Last week I noticed a couple DVD's were starting at normal speeds when writing and then dropped off to 3.5x but that problem seemed to come and go. In the last two days write speeds have been consistently below 1X.
The only recent changes I have made to my system that I can think of was installing Vista, but I installed it on a second hard drive and kept XP. Since the install I have only used Vista twice and have continued using XP. I have read all kinds of bad reviews of this drive, but was hoping I could get an answer here...even if the answer is to buy a new drive.
Other System Info
ASUS M3a78 Pro MB
AMD Athalon 64 3.2 Ghz Dual Core
After writing this I thought of one other thing that I purchased right about the time this problem started, but I can't conclusively say if they are related. I bought some super cheap "Ridata 8x DVD-R's" because they were $5 for fifty and burned one test project, which was just a 3-4Gb *.mkv file. Didn't seem to have playback issues on my system, but the write speed was slower, which I just credited to being 8x media.