When you say "does some connection to the internet", this is rather vague.
Maybe it was the installer checking for an update, maybe the program itself checking for an update?
Did you try blocking it with your firewall, maybe it doesn't need an internet connection at all?
Email the author, ask them what it's doing - it can't be anything too dangerous since they've released the source code.
If you feel so inclined, the code is available at Codeplex
, you could see what it's doing or compile your own standalone version.