Hi Apostolos, it may feel like a bug in this situation, but it is not, for the single reason that includegraphics cannot look inside the picture and decide which part of the picture is irrelevant. If you add a picture of some width and height, TeX makes sure it is completely inserted. If you turn it by an angle, TeX makes sure the whole of the picture is included and no corners are cut off. If TeX did otherwise, I would consider that a bug.
Regards, Julius
