Mone
A little digression: when running within Firefox, javascript code has not the permission to change the message in the status bar. Looking our demos you don't see "Lightstreamer is streaming" (as shown in IE6) but "Downloading data from push.lightstreamer.com". So far so good.
The issue in Firefox from version 1.0 to 1.5.0.7 (fixed in FX 2.0) is that if you are looking a demo in a tab, and close that tab, you will see that the message in the status bar remains "Downloading data from push.lightstreamer.com" until you download something from the web.