problems with Safari 5.1.10

I am having problems with safari 5.1.10 running on a minimac with os x 10.6.8.

Some websites are fine but on others it doesn't always load up images or all the content and the screen wont scroll or any links/buttons dont work.

Sometimes the a site can be fine for a while then suddenly start doing it.

One site was fine yesterday but is doing it today.

When you get a site that isn't working properly you can try to scroll down or click something and nothing happens but then if you click off safari and then back on what you had done happens!

Its driving me mad now 😕 any suggestions?

I have tried clearing the cashe and switching off IPv6 after reading various similar threads.

I though the IPv6 thing had worked as the current website I was one which was working then started working but the next page I site I tried didn't and the original one stopped again.

I'm connected to a network including various other macs using different versions of safari and different operating systems and a G5 on snow leopard with the same version of safari all of which work fine.