Hello Chris,
two guesses:
1) AV products do estimated guesses with their heuristic scans. Simply said, they take some patterns in the investigated EXE as a hint and yell. And maybe your fresh compile held such a patterns?
2) AV products get updated quite often, maybe the latest update made it more aware of communicating apps using ports via TCP/IP ?
If that Bubba complains next week still, put your app on a whitelist (if that product has such).
Or did you compile a new malware......?
Wolfgang