I earlier FF versions I didnt have that.
Only in the latest ones, currently in 3.5.12
I would like to attach an image but in the initial post people cant attach images.
I will post an example image in my answer to my post.
Thanks for the tip.
I will check everything to see if an add-on causes the trouble, although I am experiencing this problem only since I have upgraded to a later version.
The add-ons remained unchanged. I didnt even upgrade my flashplayer since quite a while.