I got also both of these errors on fresh Kubuntu Feisty Fawn install and I think they were a reason for some instabilities.
Both errors (and instabilities) disappeared when I disabled the faces completely (both settings for this).
I would recommend switching them off by default until the corruption bug is fixed so that people don't blaim (k)ubuntu for the bugs of one program.
I got also both of these errors on fresh Kubuntu Feisty Fawn install and I think they were a reason for some instabilities.
Both errors (and instabilities) disappeared when I disabled the faces completely (both settings for this).
I would recommend switching them off by default until the corruption bug is fixed so that people don't blaim (k)ubuntu for the bugs of one program.