Dvd Rom Wont Play Movies

Hi, everyone
Can anyone help? I have a Toshiba SD-M1612 DVD ROM that plays some DVD movies and not others? The movies were all commercially bought in the UK. I have Power DVD software installed. My computer is P3, Win98se, Ram356, and 866mhzCPU, 20 Gig H/D. Do I need more software? Or do I need to manipulate the computer system?
I am thinking of installing a Pinnacle Studio PC TV tuner.capture card in the near future , if that would help?
Thanks in advance for all advice. Cheers, Clearvisionman

wow 98 huh? the first thing i would do is upgrade to xp and add more ram. and then update your firmware on your dvd-rom drive.
or just upgrade the firmware. Am i right to think that windows dosent support updates for 98se anymore?

Right about windows 98se. Last month donated an older pc (98se) to a 4 y.o. next door who loves it…let him bang away…lol. I reformatted and updated just before MS yanked support, I think it was ~ July 6th or so.

BTW, never heard anything good about upgrades with xp, better to do a complete new install, but maybe that’s what you meant? No firsthand knowledge of this tho’, just what I’ve heard.

If I was you I would just get a new pc off ebay or something.

Thanks for reply nsevilgenius, think you may be right on the firmware. Where can I get the firmware? Checked firmware sub –heading on forum, nearest to my model was SD-M1712
http://www.cdfreaks.com/drive/firmware/634
What is the practice regarding firmware? Do I try out the above firmware, or try and get the firmware elsewhere?
Checked Toshiba website but my DVD Rom model was not recognised there. Possible (?) on my searching technique. Any suggestions? I am about to upgrade to XP Pro and increase the ram to 500. But I think the O/S and increased Ram are improvements in this case, it’s a lightly used unit, the DVDs that play, play great. The ones that don’t are failing at the disk recognition stage. I read ashmo reply post first, it made me laugh! Do not know anything about supporting updates, is this important to the firmware being installed?
Cheers and thanks