As far as I'm concerned Network54 have created the problem, and they really ought to solve it. Meantime however here's a workaround for Chrome users who'd like to be able to post!
Install the Chrome extension 'IE Tab'. Here's the page
in Google's Extensions Pages.
This seems to do exactly what it says on the tin. You use IE in a Chrome tab - and as IE can post on Network54, so can you! Absolutely brilliant! I can't certify that it won't rip off your data and plunder your identity, but hey, 616000 users can't be wrong - at least I hope not!