Yeah, that's how I discovered my problems yesterday, and it happens to be the case that I have a totally useless program lying around, which I can easily modify to create a test.
However the advantage of having a game is actually knowing what game programmers need and want.
Wow... I made some big mistakes...
Anyway, I created a little server and client and because of that I was able to do some testing, which meant that I'd see all my mistakes.
Fixed!