Hi all, just signed up on this forum as i have seen the problem you have with 3g and thought i could throw some light on it for you.
On Thursday i received my HTC Hero from Orange on a contract with them. It was the orange branded version. After playing about with it, i realised i could not connect to the internet, and i could not get a 3g signal. I was also having problems with my signal dropping out (sometimes for an hour or so). So i decided to give Orange a call. They went through all my internet settings, done a factory reset, reset my internet settings again but still i had no internet. They said they would escalate this problem to their technical department and ring me back on Saturday morning.
Well Saturday morning came and went, i decided to ring them back, they advised me to ring HTC direct to see what they thought of this. I rang HTC and they done the same as Orange, reset settings etc, after 1hr 20 mins on the phone, they suggested i returned the unit back to Orange as faulty.
I then phoned Orange back up, and i spoke to a guy who again, went through the proceedure of checking settings again. After 45 mins, i was put on hold, while this guy spoke to the technical department. he came back and said: "We have acknowledged the fact that a high number of Orange HTC Hero phones sold by us have software problems causing the 3g / internet settings not to connect to the network" He then said they could not return it as they do not have a fault code, therefore, he was going to "add me to the list" that was being sent to HTC to try to get this rectified.
Now, as i needed a phone, i cancelled the contract with Orange (the 7 day return promise thing) and went to Carphone Warehouse. I managed to get an unlocked HTC Hero, on an orange contract. And guess what! As it was unlocked, i got all internet and 3g etc, plus my signal was much better!
So my line is this: If you have a Orange branded Hero, and you cannot get 3g / Internet / Or get dropped from service, i suggest you throw it back to them! At the moment, Orange have confirmed that there is no fix for this fault, it is embedded within their software and HTC wont help! Good luck, and i hope this helps someone.