[Closed] Max script being random in evaluation ?

I am going trough a bunch of files and I want to make a screengrab of the object in each file. I want to have a unified appereance ot the objects. The following function is used within a larger script and when I run it in the listener it works fine. As soon as I incorporate the function into the larger script it seems like some steps are missing. There is no error reports even if I remove the disable screen redraw but it does not seem to change the fov of the camera for example. Is there a more efficient/reliable way of doing this ?

function getScreengrab Inputobject =
(
if isValidNode Inputobject do
(
screencapture 
disableSceneRedraw()
select Inputobject
CenterPivot Inputobject -- mapped method
InputObject.pos=[0,0,0]
IsoMatrix = (matrix3 [0.70931,-0.405152,0.576829] [0.704897,0.407688,-0.58044] [0,0.818317,0.574768] [-0.236806,-0.543412,-241.063])
max unhide all
max hide inv
max zoomext sel
viewport.setLayout #layout_1
viewport.setType #view_persp_user
viewport.setTM IsoMatrix
viewport.SetShowEdgeFaces false
viewport.SetRenderLevel #smoothhighlights
viewport.setGridVisibility #all false
thumboutPath = (outputPath+"\\"+GetMaxShortFileName()+"_screengrab.jpg")
max zoomext sel-- zoom in
macros.run "Lights and Cameras" "Camera_CreateFromView"
camerascreen = viewport.getCamera()
camerascreen.fov = 27
enableSceneRedraw()
forceCompleteRedraw()
screenCapture=gw.getViewportDib()
ScreenCapture.filename = thumboutPath
save ScreenCapture quiet:true
)
),

thanks,

Johan