UTW – character encoding problem

The official forum for Ultimate Tag Warrior is still down 🙁 so I’ll ask here if someone has a solution to this problem.

When I first add a tag with language specific characters, for example:
č (LATIN SMALL LETTER C WITH CARON)
it is added normaly.

The problem occurs when I go to edit a post. Instead of normaly displayed tag I get a square and not the c with caron.
The weird thing is that the problem on the edit page occurs only in field:
“Tags (comma separated list)”
and not in
“Add existing tag:”
where all available tags are listed.

So this has to be related with javascript encoding/decoding.

Simmilar problem is related to encoding those chars in urls. Instead of “/tag/čas” permalink looks like this “/tag/%E4%9Das”.

Thanks in advance.