Thank you very much for your reply.
The plugin works very well now.
But I am at a loss that the QuickLaTeX server was attacked from my IP. I work with wp-quicklatex for 3 years and I do exactly the same thing that I did 3 years ago. My site is about school physics and mathematics and it work for the educational purposes only.
I changed my login and password and I hope this will not happen again.
Many thanks
