Firefox buffer overflow @ hotspots

Hello all,
Yet another problem requiring your inputs:
I have 3 tabs open as my home pages in FFox. v2. When I connect @ home or corporate networks, I connect fine. When I connect @ a hotspot, where a login to the tmobile network is required before the browser would fetch my home pages, I get a buffer overflow error, causing FF to crash. If I use Internet Explorer to connect, I don't get this error. Suspecting that the problem has to do with the amount of tabs on my homepage, I reduce my homepage setting down to just 1 tab, but still, same problem. If I login with IE, then launch FF, all my tabs display fine, no buffer problem. So....
what's going on? I would like to understand this problem. Thanks again for all your inputs.