can’t save or publish a post, just upgraded to 2.5.1

I just upgraded to 2.5.1 and it seems to be working. Blog is functioning fine, login is fine, dashboard et al seem to be fine, uploaded a photo to the uploads page, that’s fine. But when I go to save or publish a post, it spins its wheels for a long time and then times out. “problem loading page.” Ideas?

ETA: I just tried publishing on my macbook, and it worked, yeah! But it isn’t working at all on my windows machine. Just turned off zone alarm to see if that was the problem. Still no go. Does anyone have an idea where to look? Why/how would my windows machine be blocking a post from being published???