Firefox(all versions) with an element with "contenteditable" attribute the "middle click" doesn't work (open link in new tab)

Hi,
I'm from spain.

I have a problem with Firefox (I test the v. +3.5, the v +3.0 AND with different 3.6 compilations). But with Chromium or Chrome works totally correctly.

***The problem is***:

If in an HTML document any of the elements has the "contenteditable=true" attribute the middle click of the mouse (open link in a new tab) doesn't work.

I post in a question first because i don't sure if this is a real bug.

I try to reproduce it in other systems (windows 7) with Firefox 3.5 and the -middle click works- so I think that the problem is in the version of the Firefox compiled for Linux, in especial, Ubuntu.

I think that the problem seems to conflict with the "paste event" in Linux system (middle click in gedit or something).

PS: to reproduce it:
- You can try with Firebug.
- First try the middle click works (It should open a new tab if you click over an anchor).
- with some element (like div) edit it I write or add a new attribute: contenteditable=true
- try to use the middle click.

Please if this is a bug can you convert in a bug report? Thanks!

PS: sorry for my English.