please change the tray icon displayed when in block all mode. when i leave my computer on overnight to process, I like to put the machine in block all mode, but the next day when i come in i sometimes forget and spend 5 to 15 min trying to figure out why my internet connection is down. also the ability to go into block all mode when the screen saver kicks in would be kind of nice as well.
Seconded, good idea 
ZoneAlarm has a feature like this (the icon turns into a padlock when internet access is blocked), so why not Comodo?
I also agree that the icon should change
I use this option alot when I am away from the PC, yesterday I spent an hour trying to get the PC to work only to find I put the “Block all mode” on the day before and forgot about it.
I find kind of silly the icon only changes when something is not working right… The icon should change when there are several modes engaged: allow all (green?) normal (white?) block all (red?) installation mode (yellow?) and maybe some transparent pop up messages can help too…