I saw the 2011 thread and tired things I say there.
This probelm is new. I have been able to burn this video to DVD before. Now what happens is Encore hangs when "validating media", with the bar at about the 60% mark. When I click "Cancel" Encore stops repsonding and I have to get Windows to shut it down. After doing this the CDROM/DVD drive disappears from Explorer. Rebooting brings it back.
I can export to an ISO file and burn that to disk using Burnaware, so the drive itself works.
I recently installed 2 GB drives and had to install updated RAID drivers (Intel Rapid Storage Technology, iStor). The hard drives work OK. The CDROM//DVD works OK, plays music discs, burns discs with my Encore projects and other files. Not sure if iStor is a problem.
I don't have other media programs on this computer. Mostly Adobe products and some video converters.
CPU - 2.93 gigahertz Intel Core i7 870
OS - Windows 7
Motherboard - Intel DP55KG
Video - NVIDIA GeForce GTS 250
CDROM - Not sure, I have to reboot to get it back. It's a Pioneer CDROM/DVD>Blu Ray drive.