the ZA icon blinking/lighting up shows it is stopping an attempt to hack your pc, it might only be your own ISP's ping to see if you are still connected.
one way to check is to view the log and see if you can pinpoint where the "attacks" are coming from.
as for stopping things in the task manager, maybe you are being a little too hasty, firewalls are constantl monitoring your connection and will show hack attempts from known safe sources such as your ISP as well as malicious/unknown attempts.
about every 10 seconds all the lights on my modem flash to show internet activity, im sure this is only my ISP.
if you are really worried then the paid for ZA has a location finder to show where the attacks are coming from, this only poinpoints it to a rough location (and lets face it, people who are upto no good usually use someone elses unprotected system anyway) but the majority of the attacks i found were coming from America and China. i dont know anyone there so didnt bother, my system stayed safe because ZA was doing its job and blocking the pings.
if you are really worried about your security, visit this site click here and check out the "YOUR three muskateers" programs, i run all 3 of them to protect my system. the last one is to remove the ads that come with Messenger.
I have a Netgear router/modem, and every few seconds, it 'polls' the internet link to make sure that it;s still connected. Not a lot else happens. I don't get an alarm or flashing red light if my link 'drops out' - which it does too often.
Had a look at the log and it appears that teh culprit is svchost.exe. Sometimes it is, as you suggested, contacting my isp on 192 etc. The other times is is going for 255.255.255 or similar. Anyone any idea what this is?