NEC 3550 burning problems

I have an NEC 3550 made after March 2006 (stock firmware 1.05), and have yet to get it to burn DVD’s correctly. Running XP and using Nero, I can transfer video from my camcorder and insert the chapter markers just fine, but the resulting burned DVD has glitches or freezing at the chapter markers. I have been unable to find a combination of settings that eliminates this. Burning the disc image onto the hard drive and playing it back works fine, no glitches. Playing a commercially released DVD with chapter marks works fine, no glitches. Everything on the Nero Info Tool looks good……am I missing something in the settings? Could this be a driver problem of some sort? Or perhaps a firmware problem? I would like to upgrade the firmware to get the speedups, bitsetting, and rpc1, but wanted to try to successfully burn a DVD first. Am I correct in this approach? As far as what I want to get out of a firmware upgrade, it appears that Dee’s 1.Y5 would work best in my application….am I correct in this? Would Dee’s 1.Y4 or 1.Y2 also work? Or is there some other firmware upgrade that is more highly recommended? Nothing I’ve read has enabled me to figure out this problem, and it’s been awhile, so I’m finally appealing to the experts for help……TIA!

If additional info would be of help:
AMD Sempron Processor 3000+
C51MCP51 motherboard
Phoenix Technologies Award Workstation BIOS v6.00PG
Sound: Realtek AC97 Audio
Video: NVIDIA GeForce 6100