You dont have to thank me, thank KNTRO, as he was the one who brought here the solution to our problem. 
No, Jenny (can I call you* Jenny*? :P). Nobody has to thank me. I do this because I like to help users of Mozilla technology based programs, as CometBird.
Oh, and I dont think these forums are stupid at all. I found this useful indeed. You have to learn to follow the forums rules and search for the right forum, it isnt that hard. 
You’re right. It’s important that everybody respects the rules of any forum. Most rules say that you have to take a look and search for the answers at the forum before posting questions.
Moderators say that it’s highly probable that someone else asked the same thing in the past. And they used to be right in the vast majority of all cases.
ArkNJet,
You’re welcomed to the forum, too. B)
other times I accidentally click once on the tab I have open and it closes.
That used to happen to me as well, that’s exactly why I disabled this evil function. 
I have a complaint with your answer too. You give us one fix and say “If you use other functions of Browser UI Enhancement 2.06 and don’t wanna lose them…”, well I don’t know if I do or not, How bout giving examples of what is controlled by this feature so we have an idea if we’re using it or if it’s the source of all my issues.
Alright.
The Browser UI Enhancement 2.06 add-on offers several features. All its features are shown in the
about:config setting page under the browser.enhancement prefix when the add-on is enabled.
These are all the functions of the Browser UI Enhancement 2.06 add-on:
■ Close tab by double clicking
■ Tab Group
■ Open web addresses by dragging its selected URLs text and dropping it into the address bar
■ Open web addresses by dragging its selected URLs link and dropping it into the address bar
■ Google Translate: translate a word under the cursor
■ Google Translate: translate the selected text
■ Send anonymous statistics
If you disable this add-on, all of these functions will be disabled as well.
Only the first option of the list is not present in the Browser UI Enhancement 2.06 add-on menu (I think it’s a mistake, something that CometNetwork forgot). The rest of options are there (my opinion is that all the CometBird’s default add-ons need a revision/update in fact).
So, are you using Tab Group, drag & drop URLs, Google Translate service from Browser UI Enhancement or sending anonymous statistics? If you’re not, you can disable the add-on. Otherwise if you’re using at least one of these features, you should keep this add-on enabled (you’ve already modified the Close tab by double clicking function thru the about:config page, so now you don’t have to worry about this specific function, 'cause it’s indifferent whether you have this add-on enabled or not).
I hope all this explanation be clear enough to you, ArkNJet. If you have more questions, just post them here, I’ll help as much as I can.
Best regards to both of you!