Yup. And it's odd. Another Macbook sitting right next to mine, with the same
software and configuration, works just fine. Contribute starts right up and
it's happy. And my PCs, running PC Contribute CS3, same deal, no problem at
all. So it's not Adobe's servers, or my network, or anything external -
something specific about our particular machines (Your one machine and my one
laptop) is causing this.

I sprung for the (very reasonable IMO) Adobe Bronze support contract, and
opened an incident on this. We'll see how it goes! If we find anything, I'll
be sure to post it back here.

Meanwhile if anyone else has any insight, please post!