Any dialog which have content long enough that it should become scrollable are cropped at the end (for example Initial Run tab in new VM dialog if all parts unfolded)
*** Bug 1247136 has been marked as a duplicate of this bug. ***
Verified in 3.6.0-0.15.master.el6
oVirt 3.6.0 has been released on November 4th, 2015 and should fix this issue. If problems still persist, please open a new BZ and reference this one.