Remote Desktop Connection receiving encryption error

We have approximately 40 PC's on our LAN. People use Remote Desktop
Connection to connect to their PC's from across the LAN as well as from the
Internet. Our biggest problem seems to come from PC's connecting to other
PC's on the LAN. Some PC's do not have any problems staying connected to the
remote PC, while others get the "data encryption" error and are disconnected
quite often; sometimes as often as every couple of minutes. I have checked
Event Viewer on both PC's and nothing is recorded after the "data encryption"
error.

I was wondering if anyone else is experiencing this issue and if you have
any suggestions for fixing it.

Thanks,
Bob