hmm...
According to your exif ...
First picture - iso200, pattern metering, aperture prioity, F3.5
Second picture - iso100, pattern metering, aperture priority, F3.5
The 1st shot, subject looks good and fine (by the way, nice shot)

but that burning spot ... :thumbsd: . It looks like your cam have some sort of metering or CCD problem. But to confirm this further, try taking shots with the Program mode or with higher f-stops and see if this still happens. If still the same, send back lor.
PS: I went thru my old shots (about 3000 shots) with the Z2 but it seems like it is not normal to have such effects ....
And worst come to worst ... ask Minolta for refund and go buy DSLR la ...
