Turns out that Firefox is blocking extensions with serious bugs from major companies beyond Microsoft, including Apple, Yahoo, and AVG. Here's the full list of blocked extensions and the bugs that are causing the blockage. (Ironically, the AVG extension is called "SafeSearch.") In a blog post, Mozilla security chief Mike Shaver says the .NET Framework Assistant has been unblocked, but as of writing it still shows up on the published list. Kudos to Firefox for taking a proactive stance and protecting its users against buggy extensions that could degrade the browsing experience. Did you have a buggy extension installed?

You use Firefox, you keep Gmail and Google Reader open at all times, and you wish they didn't take up so much space in the tab bar. (Maybe you're on a netbook, or maybe you've always got a dozen tabs open at once, so real estate is scarce.) You can permanently affix the Gmail and Reader tabs in your tab bar, reduce them to show the tab favicon only, and display the number of unread items in each using a collection of Firefox add-ons. See what it looks like in the image above: the Gmail and Reader tabs are on the far left, icon-only, with unread item counts--19 unread messages and 1k+ unread items (yikes!)--on the icons themselves.

To reproduce this setup in your own copy of Firefox, you'll need four Firefox add-ons which I've put all together in a single collection. Install all the add-ons in the Icon-Only Perma-Tabs for Gmail and Google Reader collection. Restart Firefox.

Then, in Better Gmail 2, make sure "Unread Message Count in Favicon" is checked. In Better GReader, make sure "Show Unread Count in Favicon" is checked. Open Gmail and Google Reader in new tabs. Right-click on those tabs, and choose "Faviconize tab." Then, to make them permanent (i.e., open automatically every time you launch Firefox), right-click again and choose "Permatabs->Permanent Tab." Once you're done, whenever you launch Firefox or even hit "Close All Tabs," your icon-only perma-tabs containing Gmail and GReader will persist. (Hat tip to the Lifehacker reader who reminded me of this cool trick!)

As always, a lively conversation about all the Better Webapps add-ons is going on on the mailing list. Hit us up with questions, problems, or requests there.

Download Better GReader and let us know what you think. My favorite feature: "Preview Item," which loads the originating web page right inside Google Reader.

Luckily, rockstar userscripter Arend v. Reinersdorff updated Folders4Gmail to work with Gmail's new drag-and-drop, hide-and-show label mechanism, and I just posted his new version in the extension. Grab the newest version 0.8.3 of Better Gmail 2 to get back Folders4Gmail functionality as well as Hide Spam Count. Check out what Folders4Gmail looks like in action in the screenshot. Arend recommends showing all your labels to get full-on subfolder action with Folders4Gmail enabled.

Also, thanks to the product manager at Google Apps who contacted me and Arend personally, apologized for making the label changes without sooner notice, and offered support and encouragement for updating the script and add-on. That was a nice big pat on the back for something a lot of developers have put time into. (Thanks also to the users who contacted Google asking them for their subfolders back!)

Until Mozilla Add-ons approves the newest version of Better Gmail 2, check off "Let me install this experimental add-on" next to version 0.8.3 here: Better Gmail 2.

The folks at Mozilla Add-ons do a great job of nudging their extension authors to make their work compatible with new versions. Still, a few add-ons aren't there yet, notably Google Gears (not hosted at Mozilla Add-ons) and Tab Mix Plus. Update: Testers tell me a developer build of Tab Mix Plus is Firefox 3.5 compatible. Thanks all!

Luckily when you install Firefox 3.5 you get a warning upfront of which of your installed add-ons aren't yet compatible, like the one I got today, pictured here. (Come on, Auto Copy and Evernote, get with the three-point-five!)

Here are a few others my Twitter followers are missing.

Yesterday I said:

Firefox 3.5 to drop tomorrow, yay! Testers, which of your most beloved add-ons aren't compatible yet?

StephanieBamBam said, "Firebug!!! Everything else I use has been updated, it's wacky to me that firebug still doesn't work." Editor: Firebug got updated!

kerim said, "I use Nightly Tester Tools to get compatibility, but Google Gears won't work even with that hack. Hoping they'll update w/ 3.5."

GuiAmbros said, "CopyAllUrls. Plasser (the author) is working on it, but no ETA yet =("

acidflask said, "google gears!!!"

sastubblefield said, "Aardvark, and Measureit are the only ones I use that aren't compatible."

NguyenNoir said, "aside from the ACE Safari theme, all my addons work just fine (oh yeah)"

billhelm said, "TabMix Plus. I uninstalled the RC yesterday because I can't stand firefox without it!"

MrMileage said, "Better GReader, GoogleAdvCookieOptOut, Drag&Drop.io, Google Gears" Editor: Better GReader is compatible!

tjunkie said, "I have so many useless extensions that works and it has to be google gears that is not compatible"

garygiffordjr said, "the last holdout for me is Verisign Seat Belt."

her_boyscout said, "seriously missing "gears" add-on..."

akumu said, "opendownload. Allows me to open downloads without having to save them first."

failedidealist said, "TabMixPlus "

Rooster212 said, "Smart Bookmarks isn't compatable as far as i know "

stephanpeterson said, "system proxy on the mac hasn't been updated for FF 3.5"

DavidWmBrown said, ""Copy Plain Text" and "Morning Coffee" are not currently working with Firefox 3.5"

melalegre said, "I'd like to have NoScript, AdBlock, GoogleGears, and GreaseMonkey fully running in FF 3.5."

ClintStrong said, "Tab Mix Plus is the main one I'm missing."

SteveFalatko said, "- sage ... yes I still use RSS feeds and sage is my favorite. Not compatible with 3.5"

robmcbell said, "GEARS!!!"

scotmathis said, "Beloved add-on not compatible with FF 3.5: Tab Mix Plus"

Ledlow said, "Automatic Save Folder didn't update after Beta 4, so I'm hoping for an update with the release"

PhYoshi said, "Judging by the fact nothing has broken, 3.5 seems to be pretty awesome compatiibilitywise (TMP, DtA, AioS, stylish, twitterfox)"

forpus said, "no problems with Nightly Tester Tools, http://is.gd/1iPcz"

Thanks to everyone who replied. Here’s more on why and how I’m using Twitter to run surveys like this.

Firefox 3.5 [Mozilla]