It looks like you are close. The webURL should point to the site (as you're trying to do).
What I would probably do next is to try running the SPServices call and debug through to see exactly how the spHostUrl value is set and then watch the Net traffic to see what's off.
M.
What I would probably do next is to try running the SPServices call and debug through to see exactly how the spHostUrl value is set and then watch the Net traffic to see what's off.
M.