Stopping Downloads in Firefox

[#1]

I opened up a live webcam  (Ware Hertford Traffic) in Firefox.  I have closed the tab, but Netmeter show that it is still down loading.  As a test Closing Firefox stops the Down load, but how do I keep Firefox open and stop the download?

[#2]

if you want experiment the web cam is at
http://www.wareonline.co.uk/webcam/default.asp

[#3]

I've seen this on other webcams - it used to happen on the Plusnet ones - but I've no idea of a fix.

[#4]

Just tried it with I.E., had to download Active X, but it did stop when I switched sites

[#5]

I tried the link and it 'appeared to continue downloading' even after shutting down FF...Hmmmm.

[#6]

I've seen it continue for 5-10 seconds after closing FF, but it does then stop.