I can also reproduce this on Ubuntu 12.10, and as this does not reproduce on Windows and OpenSuse (with KDE) I suppose it's a bug in the VCL GTK implementations of the text entry and combobox.
I can also reproduce this on Ubuntu 12.10, and as this does not reproduce on Windows and OpenSuse (with KDE) I suppose it's a bug in the VCL GTK implementations of the text entry and combobox.