Ah, I see. In that case, my only suggestions you may have already tried. Make sure you have the latest drivers for the modem and check the manufacturer's site for bug reports. If you're using the manufacturer's latest drivers, try using the Windows generic driver. If you upgraded to another OS when you changed machines, check Microsoft's or Apple's site for any reports on disconnection problems. Do a search on Google for 'modem disconnect random' or something similar. Check CL's site also - I assume you have the latest patches for your version of Poser. It's weird that it only happens when you render to a new window, but I've heard of lock-ups, etc. during that process. Good luck.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken