Hi,
I'm having much the same issue, though on an i7-930 workstation with a GTX480 w/ 1.5GB RAM. I get the Neat Video error log console pop-up, and while sometimes encoding continues, usually it fails with Premiere Pro's helpful "Error compiling movie" error message.
On occasion, I'll even get this when simply playing back in a sequence, not exporting. It is usually happening if I try to scrub through a sequence too quickly.
I've tried the suggested solution of disabling Pr's GPU acceleration for export, and that seemed to work--my export came out fine. However, it took a long time to render, so I'm wondering if there is a way to tweak NV to allow it to use the GPU as well as to let Pr use the GPU. The plug-in is otherwise awesome!
Thanks for any insight.