DVD Playback help

Hiya! I'm looking for advice/suggestions from people I DON'T know as to how to solve a problem with my computer and its pathetic DVD playback. My whimpy PII 266 laptop with a decoder card plays them infinitely better. Anyway, I have a pretty clear idea of what will solve the problem (motherboard replacement), but I would like to avoid such a costly move if at all possible. OK.. so, I'm assuming you'll want to know what my computer is:

Athlon t-bird 950 Mhz

Abit kt133e motherboard (sigh), VIA chipset

576 MB ram (non DDR)

40 GB maxtor 7200 rpm

philips cd-rw (which is in line for replacement)

generic 16x DVD-ROM drive

SB Live! 5.1

gforce 2 Ti

WinXP Pro

I have done just about everything I can think of, but DVDs will not play without lag, no matter what video setting I use. All my devices are using the IDE-80 type cable. Everything is set up in DMA mode. I try and keep as few programs running in the background as possible. I'm currently using WinDVD Platinum for playback.

One of my concerns is that the 686B Southbridge bug might be causing the problem. In case you've never heard of it (and I hope you haven't had to suffer from it), this bug affects people who use the particular sound card I have. (Of course, VIA thinks that only people with Win2K should have this problem.. HA!) Any time you're doing something where you are using the sound card and transferring data in some way (such as playing a CD, installing a program), the system lags to kingdom come. With driver updates, I can now play CDs and transfer data with no noticable lag. Playing DVDs is another monster.

Let me fill you in on some other fun facts about this computer. Both the original 20 GB hard drive and burner died in the same week, about 4 months after I pieced a new system together. The hard drive WD sent as a replacement never worked and is now out of warranty. The replacement burner Philips sent is now refusing to eject discs unless I stick a paperclip in the little hole, which leads to a lovely grinding noise from the motor (it won't spin down once a disc is put in). I previously explained the DVD playback issue. The other thing that irks me is that the video card can't run in 4x mode without causing numerous graphical glitches and computer crashings.

That being said, any ideas for the DVD drive? I'm hoping it's something simple I looked over, like maybe a setting in the bios. (Yeah yeah, I know I already have a working DVD-ROM drive, plus a standalone player, but... it's the principle of the matter

Thanks much in advance!
The 686B-SBLive! problems manifest themselves as crackling audio and HD corruption, but of course Creative's drivers are capable of anything except working correctly. Have you installed VIA's 4-in-1 drivers, or if you have updated your OS after that, have you reinstalled them?
4-in-1 drivers have been installed. Bios updates... about the only thing I haven't tried is some bios hacking... I don't trust myself enough.

Thankfully, the sound glitches aren't as frequent as they used to be, and the system doesn't lag to a screeching hault when trying to play a CD or install something. I update drivers frequently, so I'm assuming that may have helped. But I'm at a loss for DVD playback. I could understand the poor playback if this was a slower processor, but a t-bird 950 isn't exactly slow. The only thing I can think of is there is some of bottleneck somewhere.
What dvd player do you use?

Strangely, windows media player (nvdvd too) is the one wich works best when you have ASPI drivers installed.

Also. take a look for the creative and via "pci latency" & "memoty interleave" patches here, I found this very useful when trying to get unreal tournament 2k3 to work, you may try to use them for your problem.