How do I get rid of that popup asking me to "sign up for x-marks"?

== Issue == I have another kind of problem with Firefox == Description == How do I get rid of that **** pop up that asks me to sign up for ***** x-marks? I can't **** stand that, very intrusive, very intrusive... <blockquote>edited by a moderator - eh https://support.mozilla.com/en-US/kb/Forum+and+chat+rules+and+guidelines </blockquote> == This happened == Every time Firefox opened == User Agent == Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8 ( .NET CLR 3.5.30729; .NET4.0C) == Plugins installed == *-Garmin Communicator Plug-In 2.9.2.0 *Adobe PDF Plug-In For Firefox and Netscape *NPRuntime Script Plug-in Library for Java(TM) Deploy *Default Plug-in *BrowserPlus -- Improve your browser! -- http://browserplus.yahoo.com/ *Shockwave Flash 10.1 r53 *Garmin Communicator Plug-In 2.6.4.0 *Yahoo Application State Plugin version 1.0.0.7 *4.0.50524.0 *Windows Presentation Foundation (WPF) plug-in for Mozilla browsers *Next Generation Java Plug-in 1.6.0_20 for Mozilla browsers