Viz dissapears!

Viz 6 (sp1) and Vray 1.46.15.

Been getting lots of crashes which I assumed were memory problems with the VFB etc.

But, what happens is that Viz just vanishes and a STD Autodesk ‘Send error message…’ appears.

Does this suggest a Viz or display driver problem? or is this typical for VFB memory probs?