Two different computers, one W2K the other XP, both using Netscape 7.2 as the browser, same problem.  Only at Renderosity does the browser's "back" button not work after I've opened a message thread to read, for example.  Most often the progress bar at the bottom of the browser window never quite gets all the way done ("Waiting for www.renderosity .com"), and  I have to select the "Retrun to top of forum" option to escape the open thread. 

Intel Core I7 3090K 4.5 GhZ (overclocked) 12-meg cache CPU, 32 Gig DDR3 memory, GeoForce GTX680 2gig 256 Bit PCI Express 3.0 graphic card, 3 Western Difgital 7200 rpm 1 Tb SATA Hard Drives