(6/20) Update: I meant to post this ages ago, but I forgot. The issue I was experiencing with Firefox 4 was entirely my own fault. I’ve since upgraded back to Firefox 4 and haven’t seen any problems since.
I’ve decided to start using my blog again, if only as a repository for things that I come across on the web and may need to find again. Generally I bookmark these things, but I shudder to describe the state of my bookmarks folders. Yes, I said folders, for they exist on no less than two different machines, and that’s not included the backed-up versions of my bookmarks folders from multiple rebuilds, upgrades, and eff-ups across the entire span of my computer-using existence.
Before I get farther off-topic, I must say that it pains me a bit that the first post I write will describe steps to downgrade from Firefox 4 back to Firefox 3.6.17
I’ve been using FF4 for a couple weeks now, and for the most part, I didn’t notice much of a difference. However, I’ve recently been working on integrated a number of different javascript components into some client sites, and for some reason, they don’t all seem to play nicely in FF4 or Chrome 11. Namely, the Twitter @Anywhere widgets seem to cause some problems, but that’s a topic for another day.
Here’s a link to the help article where I found the pertinent downgrade info: http://support.mozilla.com/en-US/questions/820280#answer-181180
And here’s a quick screencap for the lazy:

Click to Enlarge
PS – I’m using Firefox 4 on a MacBook Pro, so your mileage may vary. I honestly haven’t tried in on my Windows machine (which is still XP even) because I needed at least one “working” browser for this last project. Since I’ve downgraded my daily-use machine back to 3.6.17, I may upgrade the XP box to 4 and see if it has the same issues.
Or I guess I could just troubleshoot the Twitter problem.