Guestbook doesn't display after entry submission

[vlad-m]

The problem is that Guestbook page goes crazy after entry submission, though if there are no any entries everything looks normal.

I did not change anything in templates or anywhere.
To call the module I use the following smarty tag
{cms_module module=Guestbook number=5 shownow=true mailnoti=mim_123@gmail.com lang=ru_RU}
Please help