Bugs have been detected with WeeChat 0.2.2: for servers using charsets like KOI8-R. When nicks are encoded with cyrillic chars, WeeChat doesn't decode them, and display and behaviour with server are buggy.

If you use KOI8-R (or charsets like this one), we recommend you to use version 0.2.1 or development version.
If you use only UTF-8 or ISO charsets, there's no problem with version 0.2.2.

These problems are fixed in development version.
A new version will be available soon, it will fix all problems.