Now I like living on the bleeding edge of browser development and so I run the nightly builds of Firefox. Given the recent change in the release cycle of Firefox, the version number has climbed quite rapidly and the nightly build now sends the following useragent string (you can find out where your browser sends using this website):
Mozilla/5.0 (X11; Linux x86_64; rv:10.0a1) Gecko/20111012 Firefox/10.0a1
So from reading this you should be able to see that I'm actually running version 10.0a1 of Firefox. It should also be clear why the check of my browser resulted in me being bounced to the unsupported browser page: Firefox/10.0a1 contains the string "Firefox/1". This is a good example of why you really shouldn't write your own browser detection code, especially as there are a number of well written and up to date scripts out there that correctly extract the make and version number and which are easy to use. And if you subscribe to the not-invented-here school of thought, then at least make sure you actually implement a sensible solution!