Believe it or not, I am having the exact same problem. GPS for my Inspire has been non-existent. I actually had a Captivate before this and you know the rest of the story with that one... Now I have the new Inspire and it is giving me the same issues. I have been to two different corporate ATT stores and tried it on multiple HTC Inspire phones there and would you believe it... a lot of the phones have this issue.
A great app to use to see the connectivity is called "GPS Status". This will show you a real-time display of the satellites your phone is hooked up to. The icon is grey with an orange satellite on it.
On my visit today to a corporate ATT store, I had them pull out a brand new Inspire and try and connect. The new Inspire barely had 1 or 2 connections. The actual Inspire floor model was connecting to around 7 satellites. We would hold all 3 phones (mine included) side by side and only the floor model was able to connect to a bunch of satellites.
We might have another Captivate issue on our hands. The workers at ATT were baffled and had no idea what to do. Obviously I would exchange it for a new one, but the new one has the same issue.
They gave me a number to call to get advanced technical support, so I will call that tonight to see what they can do.
If anyone finds out anything regarding this, please hit me up at joe3436 * hotmail * com