Firewall 5.9.219747.2195 failed leaktest (GRC) upon bootup

I did the test immediately upon bootup once the Comodo firewall Icon appears
on my system tray. It allows the leaktest to connect to GRC server and did not prevent the leak.

However, after about approx 3 min after bootup, Comodo firewall did prevent the leaktest from connecting to the GRC server.

I did the test a few times by rebooting my PC , and the issue is the same, it allows the leaktest to connect the GRC server immediately upon bootup (Test done immediately when the firewall icon appears on the system tray) but only prevents it from connecting after about approx 3 min.

My concern is that, backdoor trojans do normally connect to external server immediately upon bootup before the firewall catches hold of it.

Please look into this.

OS: Win XP SP 3 32bit
Firewall : Comodo Firewall 5.9.219747.2195 ( I did a fresh install of Firewall)
Antivirus : Avast Free Ver 6

Is the GRC program that you are using for this test white listed?