I recently started using Netcat to remotely run a specific program on my pc from another pc on my network. I've allowed its execution in my antivirus program and set the program control in ZoneAlarm Free as follows:
Access Trusted: Allow
Access Internet: Block
Server Trusted: Allow
Server Internet: Block
Problem: The first time Netcat is run, it returns immediately with error code "0". The second time it is run, it has no problem and functions as desired.
When I shut down ZoneAlarm Free and use the Windows Firewall with appropriate ports opened, the problem goes away. I've never trusted Windows Firewall since the debacle with its initial release and really would prefer to use ZoneAlarm Free.