. . . Figured it out. Just in case the problem happens with someone else. . . I had to put Renderosity Forums in my Internet "Sites Trusted to . . ." security category in Internet Explorer, and set up special permissions and enablements there in order to deal with that ActiveX graphic that someone here decided would increase the coolness factor and stuck it on every page (Outlook Express is set to share those settings). When I noticed that 1 - A marketplace link in the Ebots still worked, and 2 - If I added the DAZ forums to the same security zone, their Ebot links went dead, too. I went poking around in the custom settings and found where WinXP SP2 had quietly added a half dozen or so completely new settings and set them all to "disabled" without so much as a by-your-leave. I went in and reset them all to "enabled", and now the links seem to work okay. If anyone else encounters this, the main setting that affects it seems to be "web sites in less privileged web content zone can navigate into this zone".