Greg Burch has a great tip when developing Flash Remoting apps: Debug Flash Remoting outside the IDE (yet in it at the same time)
I build smaller remoting components that hook into a very large system. And it is nearly impossible to get that whole system running and kept up to date to test my small pieces. So I noticed that as long as I leave NetDebug.as included in my little pieces that if I have the IDE open and the NetConnection Debugger panel open it will catch Flash remoting calls and responses