I also have the same problem.
My script only works with 1280X1024 Resolution otherwise the mouseclick method is out of range.
My current solution is use a formula in computing the X and Y coords of the mouseclick func.
But, there are some cases (not tested yet) that this might not work.
What im planning to do is have multiple coords for multiple resolutions.
E.g:
Switch @DesktopHeight
case 600
;For 800 X 600, 1280 X 600,
case 768
;For 1024 X 768, 1280 X 768, 1280 X 768
case 720
;For 1280 X 720,
case 864
;For 1152 X 864
case 900
;For 1440 X 900, 1600 X 900
case 960
;For 1280 X 960
case 1024
;For 1280 X 1024
case 1050
;For 1400 X 1050, 1680 X 1050
Endswitch
Btw, im only having trouble with the height since i only have to divide the width by 2 to get the center.