inserting pictures in article is not working

hi there. first of all, thanx for the neverending work on nextgen. I have been using it since the beginning and there is still nothing better on the market.

I habe a strange behaviour in nextgen recently. It has also been registered by other users:

when I try to insert a picture into an article, the animated gif is showing endlessly not letting me chose a picture or a gallery. has this been solved already and I missed it?