Hi Robin W
As I stated, the problem occurs when using Chrome now also affected by safari.
I have not tried Firefox, but it is working in good oll IE.
After searching the net for a couple of hours I managed to find a solution.
The owner of the website didn’t have the same WordPress Address (URL) and site Address (URL)
I only needed to remove www. and the problem was solved.
I was actaully just about to post this, thanks anyways guys
I’ve disabled all plugins except the BBpress but still same situation.