AJ,
Connecting, via WiFi, or Bluetooth to the Internet is a two part process. First the connection of the Client (iPad) to the Host (WiFi/BT router, Wifi/BT enabled modem, iPhone, or the like. Then the Host's action of assigning the proper IP addresses so that the Client will have a path out to the internet. The initial connection might be made fine, but the second part - the Gateway address, and DNS addresses - might not get transfered. In which case, there will seem to be a connection, but the Internet just won't respond.. When using WiFi, it is ease to look and see if all the IP addressing is properly established. When using Bluetooth on the iPad, that's not the case.
(( EDIT )) I just disconnected my normal tether connection (WiFi) and tried to re-establish it through the Bluetooth setup (to my iPhone) and it's so tricky, that I couldn't get it to work out at all this time. I can get it, but have to try, and try, and try some more to re-learn the EXACT sequence of steps. I have MiWi and their Bluetooth-based MiWi OnDemand apps, and it's a BEAR, until the connection gets established the first time, then it gets easier.... unless you don't use it for some time (like me) and have to learn how to do it all over again.
The iPad (and especially the iPhone, when being used at the tethering agent for internet access) is really fussy about the sequence of steps that are required to get it all going right. Please give us a description of what you are doing to get connected. I won't say that I'll have a solution, even knowing that, but someone here might - hopefully.
Brian - Sent from my iPad using iPF