Mac Retina and Parallels with PCM15

Hi all,
Sorry if this is a duplicate, but i do not find others topics.
I've bought PCM15 through Steam
I use a Macbook pro Retina screen with Window 7 under Parallels
THe game starts "not full screeen" but the window resizes and it shows only the "upper left" corner of the screen.
If i resize manually the game screen goes black and unusable.
Solutions? (i've tried different setup of simulated window7 but no effects)
previous version did not had the same issue....
Thanks in advance
Sorry if this is a duplicate, but i do not find others topics.
I've bought PCM15 through Steam
I use a Macbook pro Retina screen with Window 7 under Parallels
THe game starts "not full screeen" but the window resizes and it shows only the "upper left" corner of the screen.
If i resize manually the game screen goes black and unusable.
Solutions? (i've tried different setup of simulated window7 but no effects)
previous version did not had the same issue....
Thanks in advance