STEPS TO REPRODUCE: 1. Start Firefox (with a fresh profile, for simplicity) 2. Drag and drop tabcandy.xpi file onto it, to install. 3. Restart Firefox. --> Note that the tab candy icon is there in your icons bar. 4. Go to Tools|Add-ons, or visit about:addons --> TabCandy isn't listed in extensions!!! 5. In left pane of Add-ons manager, click "Themes" bar, and then back to "Extensions" --> Now TabCandy is listed. EXPECTED RESULTS: TabCandy should be listed in the extensions list, after step 4. I'm using TabCandy version 0.3.1, downloaded yesterday from http://hg.mozilla.org/labs/tabcandy/raw-file/tip/tabcandy.xpi . The XPI md5sum is 314a23a70d7edba47405ffaff38f5370 Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.3a5pre) Gecko/20100519 Minefield/3.7a5pre

(In reply to comment #0) > STEPS TO REPRODUCE: > 1. Start Firefox (with a fresh profile, for simplicity) er, s/Firefox/a mozilla-central nightly/ (that's all I've tested)

Here's a screencast demonstrating the bug (in a fresh profile, with tab candy installed).

AFAICT, once tab candy shows up in addons manager, it stays there for the remainder of that Firefox session -- but when I restart Firefox, it's gone again. Also: As an alternative to Step 5 from comment 0, I can also make TabCandy appear in the list by clicking the "refresh" button when I'm in Add-ons manager.

Sounds like Bug 566626

Yup, sounds like the same thing. I hadn't noticed this affecting other addons, but now that you mention it, this does seem to affect NoScript on my machine too (as described in bug 566626). Marking as dupe.

Mass moving all Tab Candy bugs from Mozilla Labs to Firefox::Tab Candy. Filter the bugmail spam with "tabcandymassmove".