....... thanks for your reply and sorry for that double post.
Nothing fixed it since my 1st post.
I've tried everything possible like
driver updates, power settings etc. but the problem remains.
As I said I never had any trouble on Vista and as far as I remember it was working in Windows 7 as well after I installed it but I'm not sure anymore.
If it worked on Vista it should work as well in Windows 7, I guess.
Hopefully someone can help.
Thanks again .......