It can not be a browser (IE5.5) problem, because when a disable ZAP it is possible to use smilies.
My first forum contribution I could use them (as you can see), but now I can't ! Have not changed any configuration since...
Also I just noticed that it is (at this time) not possible to highlight a text to make it bold.
Most strange is, that all acts as a traffic light, mostly red, sometimes green.
Now I am editing my message, and it all works again !