5.2.1 Mac QComboBox popup positions are off

I've just updated to 5.2.1 and noticed that ComboBox popup appears 50~100 pixels above where it normally should appear.

It also happens with ComboBoxes in Qt Creator, so it's probably easily reproduced.

[Edit: I've just finished installing Windows version. It seems that the bug is limited to Mac version]

Steps to reproduce:
0. Plug in external monitor to Mac
1 Open Qt Creator 3.0.1 (which comes with Qt 5.2.1)
2. Click on Edit button on the left side
3. Click on Open Documents
4. See attached image file.

I just found out unplugging the monitor makes the problem go away