Cyrillic letters in Mercurial commit log appear as "????"

When I write a commit log message in cyrilic (Bulgarian), my messages appear as "????" on some of bitbucket's pages.
I'm using Eclipse with MercurialEclipse 1.7.1 (http://javaforge.com/project/HGE) on Ubuntu Linux 10.04. And I'm pushing via SSH. My Mercurial version is 1.6.3.

I believe I'm sending all data in UTF-8.

As I said, this is not happening on all pages, only on some (not sure if there is a rule - it varies). Currently there are some changesets which I see as "????"s on dashboard page, but when open the corresponding changeset page, the log message inside is just fine. Moreover, at some point (say day or two), the commit messages start to appear normally.

Is there something I can setup here at bitbucket site, or on my computer in order to solve this problem?

Thank you.