A few things to look at -
1) The VS Intellisense complaint about the gzipMessageEncoding is innocuous. As long as IdeaBlade.Core.dll is available at run time, you can use this encoding.
2) The bindings need to be the same on both client and server. Your client binding still has the gzipMessageEncoding defined but has commented out the bindingElementExtension. Make sure that both sides either use gzipMessageEncoding or do not.
3) If you're using the ServerConsole as the BOS host, then rename the server config file to ServerConsole.exe.config, if using the Windows Service, then name it ServerService.exe.config. The same logic applies for your client, make sure that the .config in use at run time is a loose config file with the same name as the executable. The reason for this is that the serviceModel configuration won't be processed correctly from a config file which .NET doesn't see as the application's configuration file (DevForce will see and try to read the serviceModel information in a config from a non-standard location, but it doesn't always do so correctly.)
If you're still having problems, post the entire contents of the debug logs from both client and server.