The default behavior of Firefox (all versions) will open a link or bookmark in the current tab when clicking only with the left mouse button. '''To open a link or Bookmark in a new tab''' you can do any of the following: *press the mouse scroll wheel on a link or Bookmark *hold down the CTRL key while left-clicking the link or Bookmark *right-click the link or Bookmark and choose "Open in a New Tab" *See: **http://www.7is7.com/software/firefox/shortcuts.html **https://support.mozilla.org/en-US/kb/Mouse%20shortcuts Some Add-ons allow options to open links and/or bookmarks automatically in a new tab by using only the left click button. You may have had such an Add-on in Firefox 3.6 that 1). is out of date and needs to be updated, or 2). is no longer being updated by the developer of the Add-on and is not working in Firefox 10. Add-ons: *https://addons.mozilla.org/en-US/firefox/addon/open-link-in-new-tab/?src=ss *https://addons.mozilla.org/en-US/firefox/addon/tab-utilities-lite/ *https://addons.mozilla.org/en-US/firefox/addon/tab-utilities/ *https://addons.mozilla.org/en-US/firefox/addon/tab-mix-plus/ '''If this reply solves your problem, please click "Solved It" next to this reply when <u>signed-in</u> to the forum.''' ------------------------- Not related to your question, but... You may need to update some plug-ins. Check your plug-ins and update as necessary: *Plug-in check --> http://www.mozilla.org/en-US/plugincheck/ *'''''Adobe Shockwave for Director Netscape plug-in''''': [https://support.mozilla.org/en-US/kb/Using%20the%20Shockwave%20plugin%20with%20Firefox#w_installing-shockwave Installing ('''''or Updating''''') the Shockwave plugin with Firefox] *Adobe PDF Plug-In For Firefox and Netscape: [https://support.mozilla.org/en-US/kb/Using%20the%20Adobe%20Reader%20plugin%20with%20Firefox#w_installing-and-updating-adobe-reader Installing/Updating Adobe Reader in Firefox] *Shockwave Flash (Adobe Flash or Flash): [https://support.mozilla.org/en-US/kb/Managing%20the%20Flash%20plugin#w_updating-flash Updating Flash in Firefox] *'''''Next Generation Java Plug-in for Mozilla browsers''''': [https://support.mozilla.org/en-US/kb/Using%20the%20Java%20plugin%20with%20Firefox#w_installing-or-updating-java Installing or Updating Java in Firefox]