When Aware IM previews a form it connects to a web server using the following parameters defined in the UIConfig.props file:
a) WebServer
b) WebServerPort
If it cannot find the first parameter, it defaults to localhost. If it cannot find the second parameter it defaults to 8080.
If your error message says that it cannot connect to localhost:8080, then both parameters are not defined in the file. Are you sure these settings are defined in your UIConfig.props file? (the file must be in the same directory where you start Aware IM - presumably BIN).
Does the error message change if you change any of these settings in the file?