Vista Tutorial - This ought to be simple to do (WPF ToolTip problem)

I have this Image control on a WPF form, displaying a bitmap displaying some
run-time generated stuff that the user can interact with.

Now I want to display a ToolTip when the mouse hovers over the Image
control, and move and update the contents of the ToolTip from within the
Image control's MouseMove handler as the user moves over things she can
interact with.

I can update the content of the hint just fine, but try as I may (using any
old set of ToolTipService properties), I can't seem make the hint window
move from its original pop-up location.

Also, I want the hint to always be displayed when the mouse cursor is over
the image, regardless of whether the window has focus/is activated.

How to do that?

TIA

- Per

P.S.: Is there a more appropriate newsgroup for WPF questions now that it's
out of beta? - I didn't find any on the MSDN managed newsgroup page.