When I work from home I open up Firefox and load my company's website. Upon logging in I'm asked to install a Citrix plugin. Without this plugin and I cannot launch my applications from home so I installed it. If I open a new browser while the old one is still open or if I open a new tab and surf on the net the browser continually freeze. This stops completely once I have no Citrix connection anymore. Even though I don't close the browser. I don't remember having this issue with Firefox 3.x.