Wrong utf8 encoding in subject header field

I’ve noticed that after my migration from sqlite to mysql, there started
appearing wrong Subject header fields in emails sent by rt. I’m using rt3.6
from debian lenny.

I’ve looked into the database and given Attachments have this wrong Subject in
the Subject column. The problem I’m unable to resolve is, if this can be a
problem when someone sends email as a reply to this ticket, their email client
creates this wrong Subject field and rt just copies that, or if it is a problem with
utf8 encoding inside perl.

does anyone have similar problems?