This is just a minor glitch I've noticed in mh_phoenix (rev 750 and earlier). If you use mouse to rotate mesh it will only rotate 360 degrees, then it'll get stuck. However, if you release mouse button and then re-press it, the mesh is possible to rotate beyond 360 degrees anyway.
My suggestion for more intuitive function would be to allow the rotation to continue without having to release mouse button, ie not block it once it reaches + or - 360 degrees after mousedown.