I have a small collection of VOB trailers that I like to play before watching a DVD on my HTPC. I previously was planning on just playing the VOBs off of CD-R but my DVD/CD-ROM cannot seem to keep up with the VOB data rate via CD playback (my best guess). So I decided to upgrade my 420MB HD (yeah I know, pathetic!) to a much nicer 20GB Maxtor ATA66 5200RPM drive. Playback of VOBs is now MUCH smoother and the audio doesn't lag at all anymore. The problem is that I can notice a dropped frame about every 10 seconds or so. I have a PIII 450 OC'd to 550MHz, 128MB PC133 SDRAM, PowerDVD v2.55, Win98 first edition, and the Maxtor 20GB UDMA66 5200RPM HD w/DMA enabled. Anything there look suspicious? DVD playback is fine - no dropped frames. I didn't invest in a 7200RPM HD because I didn't think it would be a requirement for playing VOBs back w/o dropped frames. Is that reasonable? Can someone explain how playback of VOBs via DVD-ROM is less prone to dropped frames than playback of VOBs on a much faster HD? Maybe Windows constantly accessing the swap file during playback? Thanks guys!