Can't assign keyboard shortcut with Meta modifiers

I'm trying to assign new keyboard shortcut for some command with using of Meta (Windows logo) key.

But instead of expected "Meta+O" I see grabage in "Key sequence" field like that: "ៀ, O". Old keyboard shortcuts that was assigned in QtCreator compiled with Qt 4.8 are shown in list, but not usable - it didn't react.

Also when I try to assign shortcut containing Alt (Alt+O), created Key sequense is "Meta+Alt+O" instead of expected "Alt+O" and didn't react also.

I suspect this issue can be Qt 5.1-specific, because this is not reproducible with Qt 4.8 and works as expected.