"some webpages are not responding" error

I am really tired of this error.

Some webpages are not responding. To

visit the selected webpage, 3 webpages in

other tabs and windows must be force

reloaded. Do you want to visit this page?

Force reloading might lose information

you’ve entered.

It happens with 3 tabs and more, and for reasons unkown. Other than when I do other things and come back to Safari after a period of time.

It is off and on. sometimes I came back after 4 hours away, and Safari does not give me that, others times it does, and sometimes after 5 minutes.

Chrome, Firefox, and Opera have never given me this error, nor have had a problem

this IS a new error, or problem since Safari 6. it has been going on for quite sometime, and I just got tire of it today when it ruined input I was doing.

Why does Safari have this problem?