phpbb3 -> vB4: character encoding trouble
 

I'm trying to import phpbb3 data to vbulletin. My site is in Czech language.
When importing with Impex, some of the special characters are replaced with ?, for example the group named "Čten?řsk? krou?ek" becomes "?ten??sk? krou?ek".

The mysql database charset is set to UTF8, collation to utf8_czech_ci. Forum language is Czech with charset UTF-8. The phpbb3 tables and columns are utf8_bin, vbulletin tables and columns are utf8_general_ci. I tried changing both tables and columns of phpbb3 and vbulletin tables containing the user group data to utf8_czech_ci and ran the "import usergroup" script again. Still, I got the ?.

If I add a group in ACP, I get things like "?Œten???™sk?©".

Help? :(