2.76, pretty sure it's in 2.77 also.
Short description of error
If you use the second orbit view fast enough before the first's "Smooth View" finishes, the degrees are messed up. Orbit view is usually 15 degrees, but since you hit the key/other shortcut fast enough when the view is like halfway through the "Smooth View" process it doesn't add up as 30 degrees but like 26 instead. This is a problem for me because I usually like the smooth view, it is better to see the slower view change than be confused for a short moment.
I bound orbit view from NUMPAD to Alt+ mouse roller and Shift + mouse roller so a lot of times I am faster and therefore the complete angle is 84 or 87 degrees instead of 90 and I have to redo the whole process.
Exact steps for others to reproduce the error
Use orbit view (NUM4, 6, 8 or 2) fast enough and have "Smooth View" in User Preferences > Interface enabled.