I am also having a similar issue. I can operate any switch or control just fine with the mouse cursor even zoomed out a little but some dials and controls no longer show the info by just hovering the mouse cursor over the dial/switch/control when even slightly zoomed out.
Trying to play at the default virtualcockpit zoom (0.7) level negates the need for the cursor-tip info anyway as the view is so close to the dials that the tool-tip info is not needed, but all i get at the default zoom level is a screen full of gunsight and isn't a very practical view for me. I havn't altered the FSX default zoom at all but change it myself for each individual aircraft.
Its only a very minor niggle to what is another absolutely stunning A2A aircraft. I also own the accusim-ed B-17 but had not loss of cursor-tip info using that aircraft.
If anyone had the same niggle and got the cursor-tip info working plese let me know how