Private Firewall Alerts

I recently installed Private Firewall and while the overall impression is very positive, I am a bit baffled by some of the alerts as they don't always provide useful information. Several times I now have alerts about PID... without any further hint as what exe or dll this may relate to. Just now I blocked PID1096040772 - nothing broke (yet) but I don't like to make decisions in the dark.

I checked the log but can only see some ICMP (1) Destination unreachable.

Under Process Monitor I strangely see the top row with an application without name or version number (ie a blank line) starting with a ? but having a filter rule.
Double clicking this shows me the rule set but application path and image path are blank. What does that mean?

Not sure where I should look for more info.