Image show in FireFox en IE but not Safari

Help guys,

I have been searching for hours now. I still have no clue how to solve this issue. In my posts there images. These images are shown fine when I am using Firefox (on my Mac) or IE (On my windows computer) but the Images are not shown when using Safari (on my Mac obviously :))

Anyone any idea why this is? And how to solve it?

Thanks!
Stefan