Does this happen in Safe Mode?

I have the same problem. Works in safe mode, though.

Edit: Disabling the Tab Mix Plus addon fixes the problem.

Thank you! That fixed the problem. Very much appreciate your help.

Disabling the Tab Mix Plus addon fixes the problem. ..

Not...!!!

You lose everything ..Ability the hoover with mouse....Tab customization..ect..ect.. Tabs drag and drop ..ect..ect...Open tabs when you point to them..ect..ect..

To temporarily correct this Problem .. You "do" have to revert to to earlier version.. and / or "wait"....Until Tab Mix plus can be updated for FF 8.

Tab Mix Plus Dev-Build 0.3.8.7pre.110917... Works fine with FF8. on my rig...Especially the function don't load tabs until selected.. Which is a major boost the Firefox 8 start-up with multitask (Tab) sessions active..

How:To:

1. Disabled Tab Mix Plus: (Add-on Section)

2. restart FF 8

3.Download install (Allow-except on pop-up) / Tab Mix Plus Dev-Build 0.3.8.7pre.110917

4. restart FF8 (If requested)

4. Enable Tab Mix Plus Dev-Build 0.3.8.7pre.110917

5. restart FF 8

link: http://tmp.garyr.net/forum/viewtopic.php?t=10888

source: http://pipecuts.wordpress.com/2011/10/04/tab-mix-plus-dragging-broken-in-firefox/?like=1

Hope this info helps...?

I just went to the link you provided (http://tmp.garyr.net/forum/viewtopic.php?t=10888) and downloaded and installed the latest dev version:

http://tmp.garyr.net/tab_mix_plus-dev-build.xpi

...and it fixed the problem! I did not need to go through all the steps you did, just installed the addon and restart FF and done.

Thanks!

just did the fix for my mac and it works fine. awesome. thanks

Tor Button addon was the cause in my case.

..and mine too in "debian/experimental's iceweasel 14.0a2 (2012-05-11)" case... Thank you for the hint.

Torbutton was the the culprit. Disabled it and I can rearrange and move around tabs again.