Ensure you compile with -use-network="true".
When developing apps it might not matter, but once you upload to the server it needs to be true.
Thanks for the reply Greg but unfortunately it hasn't fixed it. I did notice that the -use-network=true option resulted in my assets and css being separated out into seprate files.
OK, I have some more information. Cutting the IIS server out of the equation...
If I launch the app from bin-debug, it works.
If l launch the app from bin-release, data functionality does not work.
If I copy the bin-debug folder to a new location on my PC, data functionality does not work.
This suggests to me that (a) the files in bin-debug are using hard-coded paths and (b) the release is not being built properly.
Any more ideas on why I'm losing data connectivity when creating the release build?
I figured this out out in the end. I needed to put a crossdomain.xml policy file into the root of my WebOrb site allowing access to the site that hosted my app.