In Firefox, editing screen cuts off bottom of posts

When I edit posts in Firefox, with multiple tabs open, certain of my posts (such as this one, this one and this one) keep on having two problems.

First problem: When I switch tabs and then switch back, a huge portion of the post (the bottom half) disappears from the editing screen.

Second problem: If I reload the page, the bottom half will reappear (at least until I switch tabs again). However, reloading the page causes the “post status” to switch from “published” to “private.” This happens even though I virtually never open the “post status” drop-down.

These errors are a pain in the neck in general, and catastrophic if I don’t notice the errors have occured and hit “save,” thus losing huge portions of the post or making the post invisible to my readers.

I’ve tried reproducing the error in Opera, but so far the error only happens in Firefox. I did not have this problem before I updated WordPress. And I use the old-fashioned edit screen, not the WYSIWYG edit screen, in case that’s relevant. And the error has so far only occured on fairly long posts.

If anyone has any ideas, I’d really appreciate hearing them. I edit posts a LOT, and use the tabs function a LOT when writing posts, so this has seriously impeded my blogging.