TMP RULES OK! Rated 5 out of 5 stars
DEVELOPERS NOTE: Would it be possible to add the following functionality. To have a the ability to stack tabs on top of each other. For instance, you are looking for an widget on the web, you find a number of websites related to your search for the widget. You then have a lot of tabs open which can be confusing, so, all you have to do to clean-up is group the tabs together, you just drag all the related websites on to one single tab. Then to access the sites, you just right click on a single main tab and it shows a menu option with a list of all the sites you have been surfing, you will have a stacked list of related tabs. You just click on the list item to open the tab you want or click a the main tab to stay on the main website you where looking at.
'freewol' your review is really confusing what are you trying to back up every day, your last session/tabs I presume? If you are, Firefox will do that with it's built-in restore session, or you you can disable that feature in TMP (Options > Session Tab > uncheck), then use TMP's Start/Exit|Restore|Preserve options. But, the best way to manage your sessions is to install the Session Manager Add-on which is compatible with TMP. Once installed TMP will automatically detect Session Manager and disable it's own manager. Session Manager has lots of session options, such as: 'Save backup on browser restart'; 'save as' and a history session list, plus lots more too numerous to mention.
You say that: "Because of that, once again, I lost a lot of tabs today" and "mozilla.org just lost my message" is there something wrong with your computer or Internet connection - if there is, it's not the fault of Tab Mix Plus!?! I have used TMP for years and I have never 'lost' any tabs - ever. My advice is to disable all your add-ons except TMP to see if that IS the problem. Then check all your other Add-ons one-by-one and also check your computer and connection before giving out bad reviews.
TMP has had 1550 reviews and counting with an average of 4 Stars, giving it one star because it's lacking a "major feature" or your computer is having problems is ridiculous for such a great Add-on. Gary Reyes who developed this Add-on must have spend a lot of time and effort on it - and before you ask I have no connection whatsoever with Gary Reyes, I just appreciate what he does.
I am using FF4 with W7 Ultimate (x64bit) and with numerous other Add-ons installed and have had no problems with TMP and neither have 1,000,000s of others.