I just purchased a Sprint HTC Hero and found a strange bug that I thought was worth letting others know about. The long story is below but the short answer is that you can't have a "space" in your Exchange user name. When trying to setup integration to my company's Exchange 2007 server I was getting a "Could not Communicate with the Server" error. I verified and re-verified the server address, domain, password and user name but no luck. During one of my many attempts to try the setup again I mistyped my user name leaving the space out of it and the error message changed to "could not authenticate user". Ah ha! It could talk to the server but something was wrong with the user name. I put the correct one back in (the one with the space) and same error as before. Take the space out and get the authentication error again. I had my administrator change my user name to remove the space and sure enough it synced up with no issues. There must be something about how the "space" character is transmitted that the server did not recognize. The same user name with the space worked just fine on my previous two Windows Mobile phones. I don't know if this is universal to all Android phones or just this one but hopefully this post helps others who might have the same problem.