Ok, but I do get it to only 750ms delay. Here's one way how I can do that:
1. start the server, source Winamp starts playing
2. (quickly) connect the receiver Winamp
3. now you can pause the source Winamp
4. wait until the receiver catches up to the point where the music stops
5. now when you play again the source, they are almost in sync!
So, how to force to have this server buffer to minimum? Obviously that buffer must be set somewhere, perhaps it's not user configurable.