I was trying to find an article that i thought was on the phandroid news site about the whole fragmentation thing. Since I can't find it I'll try to sum up the ideas of the article. Yes there are at this very moment 5 versions of the android system out int he phone market (obviously including Froyo). The reason there are so many is because Google is updating and innovating android at its own pace. Since systems like windows mobile and the like are bought by the manufacturers like Motorola, HTC, etc, Microsoft has to hold back on its updates so that smaller companies with limited resources can update the equipment that runs the platform. With android being free for these companies to use, Google has no obligation to hold back and can update at will. What happens, which is going to be an answer to your question, is that you have phones that though they are running android as a whole, they are simply not capable of running the newer versions of the os. I'll give this example, take an older Palm Centro and a Palm Pre. Both are running the Palm os, but the Centro wouldn't be capable of running the newest version of WebOS. This is the same idea of what is going on with android, just at a much faster rate because Google isn't have to slow down and wait for the stragglers to catch up, they can just fall back and use 1.5 or 1.6 and still have a decent phone. Now you can always go the route of rooting your phone, which if that is what you decide to do then by all means, I have and its awesome. You just have to be mindful of the limitations of your hardware. Hope this helps.