This is something I have complained about several times. In my experience 4191 will not handle GLX connections from anything other than another linux/nvidia box, even though earlier drivers work just fine. Please send your experiences along to firstname.lastname@example.org
... remotely displaying GL apps to a linux box is IMNSHO an extremely important feature that (at least in the past) has a been a very strong point in favor of the nvidia drivers since certain other drivers <cough>DRI<cough> don't do this properly.
In the past email@example.com
has been pretty repsonsive ... at least as far as the bugs I report appear to be fixed in the next release. So lets make sure that nvidia is aware of how their customers are using their products so they will be sure to properly test them before future releases.