As Pete Chown mentioned, this bug isn’t related to Thunderbirf itself; I faced this bug with Opera as well, however it never occurs in Ubuntu 12.10 Qantal or 13.04 Raring.
As Pete Chown mentioned, this bug isn’t related to Thunderbirf itself; I faced this bug with Opera as well, however it never occurs in Ubuntu 12.10 Qantal or 13.04 Raring.