Yes - after 5 reboots it went away.
But then, i decided i wanted more than 60fps on CSS so i had to trun V Sync off. And oh deer, whenever i laucnh the game now theres a terrible humming (like a fly, as loud as one too) and the tone changes depending on what option in the menu i click on.
It's really ****ing me off now, sorry for the profanity but it's driving me insaine.