Can't read or write DVD-r, dvd+rw's and cdr's work!

I think I may have the same problem. I have the same brand and since my latest reinstall I can't burn any DVD-R (the same ones I could use no problem before). Nero 6.6.0.15 (demo version, but that's fine as I always used demo versions) goes to the burning window, it says "caching", the bar runs to 100 per cent and then nothing. I can't even close to window - not even brute force - and usually need a cold reboot (worked once with restart, though).

I have some possible culprits:
1. I installed VIA drivers this time, the original package I got with the motherboard 3 years ago. I know, I guess I could need an update, but that's not why the burner isn't working now. Probably it's because I installed those old drivers though.
2. The utility which came with that driver shows that the drive is set to "Multiword DMA mode 2", but it supports Ultra DMA up to 2...shall I set it to any of those, instead? I don't know what it has been set to all the time because I have no clue about DMA modes...
3. I noticed that whenever nothing is in the drive, XP identifies it as "DVD-R", if there is a CD inside it's "CD", but if it's a DVD it's still "CD"...is that normal or is something up with that?

First, let's hear what you say about it. I don't want to mess up anything by deinstalling and reinstalling drivers or setting wrong modes...

I almost forgot: I didn't test any other DVDs but DVD-R so far. CDs work just fine.

Edit: It's fine now. The VIA drivers, indeed. I deinstalled them and now it's back to normal. Duh.
But still...pio, multiword and ultra...if anyone could explain what's best for what and why or provide a good link, I'd appreciate it.