unity panel inaccessible/edge actions inconsistent on dual monitor setup

[hife]

On a dual monitor setup on Ubuntu 13.10 consisting of:
- display 1: Laptop monitor as main display with launcher on the left and
- display 2: external monitor with higher resolution plugged in via HDMI to the right of main display (no launcher) in such a way that one or more of the top and bottom edges don't line up.

I'm experiencing the following issues:

1. When the top edges of display 2 is above that of display 1, the top panel menus and indicatores are often, but not always, inaccessible by moving the cursor over it on display 1 (working fine on display 2). When activated by keyboard shortcut, mouse movement on the panel works as usual (switching between window menus and indicators).
1.b) Sometimes a variant occurs, where only the menu items in the centre of the screen are affected, but those close to the sides of the screen can still be accessed via mouse.

I am not sure if this is related to:

2. Edge actions may become inaccessible on dual monitor setup. Again with two different resolutions, e.g. if the bottom edges do not meet and the right monitor's bottom edge is below the left one's, an edge action assigned to the lower left corner is not accessible.

Both issues were already present at least in Ubuntu 13.04.

[Stephen M. Webb (bregma)]

What version of Ubuntu and what version of Unity are you running?

Is the smaller monitor on the left or on the right?