ImageHeight Bug with ATI ??

I have here a funny thing.
I get a Memory Access Visulation Error here

menu = LoadImage ("menu.png") >> no Error !!
MidHandle (menu) >> no Error !!
MaskImage (menu,255,0,255) >> no Error
High=ImageHeight (menu) <<< crash !! Error Memory Acess Vis.... why ????

this Problem exist only with a ATI Graphic Card X800 512 MB, WindowsXP and DX 9. Other Graphic Cards works fine.

where is the fault there?

Maybe image is too big. You cannot create or load an image that is bigger than the windows desktop. (It may work on some machines, but it's more like russian roulette). FOr example on my machine it mavs with 4096*4096.

You should always check for success in loading an image before trying to do something with it.

if menu > 0 then
MidHandle (menu)
MaskImage (menu,255,0,255)
High=ImageHeight (menu)
else
; uh oh!
end if