Two bugs:
1) On snapping an object's rotation centre to the intersection of two guides, the guides light up (green and red) as expected and it appears to snap okay, then on releasing the mouse, the rotation centre jumps off the intersection to a new location. This can be confirmed by zooming in to see the new location of the rotation centre.
2) On using the mouse to move the object's rotation centre, and rotating the object on the canvas, the R: field in the Transform inspector shows the angle of rotation, and the object is rotated around the user-defined rotation centre (This is expected and fine). However, when using the R: field to fine tune the value, the object won't rotate around the user-defined rotation centre. Instead it rotates around the point identified on the Transform Inspector's 9-point grid; the user-selected rotation centre on the canvas is ignored.