Unwanted connections?

Now Eset Smart Security alert me about Inbound traffic:
Application: LSA Shell (Export Version)
Publisher: Microsoft Windows Component Publisher
Remote computer: 82-39-123-53.cable.ubr04.newy.blueyonder.co.uk (82.39.123.53)
Local port: 500 (isakmp)

And question is: shall I Allow or Deny that communication? I don´t know if this is secure or is that attem for attack. At moment I get that message I just watching the movie, nothing downloading/uploading.
Thanks for reply

 

It seems you don't know the sourse , so block it . And remember the rule to block all traffic coming from that IP 82.39.123.53

 

Yeah, that´s good idea but I see similar message free four times per day, and last I´ve block something unknow, my internet connection set off.
Sometimes helps switch firewall to automatic mode for a while and return it to interactive mode, but just sometimes. After that I must set all rulles to Ask and start again .
How can I recognize bad/good connection?

 

ESS gives you a red screen for real bad boys.

 

Wait a minute... Red message mean incoming connections independently of security state, isn´t it?