opened the new 'info bar' thing with the warning

XP pro SP2, IE6

Just tried again and figured out what's happening.

Clicking the windows download link ([link|http://ftp.mozilla.org/pub/mozilla.org/firefox/releases/0.9.3/FirefoxSetup-0.9.3.exe|http://ftp.mozilla.o...oxSetup-0.9.3.exe]) from
[link|http://www.mozilla.org/|http://www.mozilla.org/]
The file downloads as expected.

However, going to the Firefox page ([link|http://www.mozilla.org/products/firefox/|http://www.mozilla.org/products/firefox/]) and click 'Download now' generates the message. The message is generated because the 'download now' link brings up yet another page which automatically requests the download. It is a security feature because the user didn't actually request the file to be downloaded, the browser did.