Why do theme functions only run once?

[gnat]

Seems like this problem has been around for some time.

Form field set by URL parameter

Hello rhuk, thank you very much. I would not have guessed. My first try works great. I added an URL parameter and the form was filled by the given value - great. But from that point on every page refresh doesn’t change the default value: The field was filled with the value I entered first. It makes no difference whether I give no parameter or another value. When I call the form with another Browser it still shows the first value. I set the cache_enable: falseoption, but it makes no difference…