'Safari Cant connect to server' - but only happens on my mac to my websites.

This has been driving me mad for months... any suggestions please help.

About six months ago Safari on my macbook pro suddenly would no longer connect to my own websites... the message 'Safari can't connect to server' is displayed. The strange thing is that the websites load fine on any other computer without any trouble and also I don't have problems connecting with any other sites from my mac... just my own, which is infuriating!

Even when trying to connect to my server to update my site via cyber duck I hit the same problem...I'm unable to connect from my mac while experiencing no problems from any other machine.

I've tried resetting safari, dumping the cache etc but no luck..any suggestions?

(Am running OS 10.7.4)

Thanks.