Vivito Volare

Currently using 2.6.2 Problem has existed for me in all 2x based veiwers, including the TPVs Running Nvidia 9800 GT with most recent drivers. Athlon x2 400+ 4 Gigs of Ram 0% packetloss 50 to 120ms pingtime, depending on the sim. Controls are exceedingly jerky. As I walk, it looks like frames were being dropped. Watching the stats bar, I see FPS jump about erratically. In the same locations, 1x simply don't do this. I can run both viewers side by side with all the same settings and the effect is the same: jerky movement and animation in the 2x viewer, but not the 1x one. What changed?(ok, overly simplistic question, I know) Is this a known issue? Is there something I can tweak to clear this up? I could not find anything relavent in the JIRA that wasn't very old. Any help is appreciated.