Jippik, I am unable to confirm this issue. Could you please provide the OS/Web Browser that this issue occurs in?
In addition, it appears you have custom third party scripting on your website which could cause this issue, if you (or the external provider) has updated this script recently it can lead to problems like this if it interacts with the uCoz CSS structure. I would recommend removing third party scripts if this behaviour reoccurs.
On an indefinite leave of absence.