Add a new pager gadget, position it to your desktop, open your virtual desktop settings and add or remove desktops, your gadget resizes in a very broken way (it should be not resized)
There is another point in:
If you create a new shelf and solely add the pager to that it will set itself better than as to desktop or as a desktop overlay.
Resizing the pager to a larger up to maximum size makes it flicker (but not with all sizes) i.e renders it useless.
The pager in the bar starts "shaking" the moment you create multiple horizontal rows of VirtualDesktops.
I suspect it's a size issue too i.e they wont fit within the constraints of the ibar size setting.