Offers only two choices: Allow always / Block this Instance - not "Allow once" ? ;-)

 

I am a noobie to NIS 2010 - I have Automatic Program control turned off, so I can get a feel for what is accessing the Internet from my machine.

 

So sometimes I get the pop-ups alerting me to either Allow always / Block this Instance.

Other times I get 5 or 6 choices - I can't remember them all.

 

What is going on under the covers in NIS that sometimes allows only the two choices... when the one I would like would be  "Allow this one time" ?

 

Thanks!