half transparent window titles?

Hi,

did anyone else notice that since a few weeks, window titles are
somehow not refreshed and/or half transparent?
I'm typically using virtual desktop mode in Ubuntu Linux.

This is observable with winecfg, the "update .wine" requester,
winetest as well as Wine's crash dialog.

A search for "transparent" found nothing related in bugzilla.

Regards,
    Jörg Höhle