Thanks for reply. I am using Dragmath in 'Lesson' window. The only third-party plugin I am using presently is moosh.
I have installed moodle on Fedora 17. I do not know if the problem of equation display right at the bottom relates to some other file not directly connected with moodle.
On CentOS 6 the same thing is working well.
Is there any other easier way to install some other equation editor if not dragmath? I will be grateful for response.