I'm having the exact same issue! I contacted HTC Support in Denmark, and they got back to me suggesting that it might be some DNS related problem. They asked me to try going to
74.125.45.100 in the Hero browser - it's the ip address for
Google.
It worked!
Then I got all exited, and continued following their instructions. They asked me to go into Advanced Wifi settings (press Menu when on the Wifi settings screen) and scroll down to Static IP and set the two DNS servers to the OpenDNS ones (208.67.222.222 and 208.67.220.220).
So I did that... and still no luck! I can't browse to regular domains, but IPs seem to work... WTF?
So it appears to be some kind of DNS issue, but a very weird one!
BTW My router is a D-Link DI-524