I've encountered this problem a few times and would like to know if there is a fix. I was working through a tutorial I had found where you link objects in your animation. The animation consists of 2 ships, one is poly, the other is nurb.
When I animate, I can see all the movement in the wireframe windows, but when I try to animate as an avi, it doesn't create anything. The globals are set correctly and the log shows something to the effect of "cannot find ship2" even though it shows up fine in the wire views with hardware texture and shading on.
I really hope I explained the problem well enough with enough information.
Nothing is more annoying than woking on something for a couple of days and then finding out it just won't work