arcpy - ArcGIS Geoprocessing Script runs fine in Desktop but crashes as Geoprocessing Service?

I have a small and simple geoprocessing script that I am trying to expose as a geoprocessing service in ArcGIS Server 10 SP4. The script is below. Pardon the hard-coding...

With the hard-coded variables, this script runs perfectly fine in desktop. However, once published as gp service, it crashes in a bad way, like I can't even trap the error. The exact message in the GIS Server log - "Container process 6436 has crashed on machine westchamp24-pc."

A couple of potential causes I can eliminate right off the bat:

1. Permissions: The entire D: drive is wide open to the 'Everyone' user


2. 
   

   Licensing: ArcGIS Server is licensed at Enterprise level

   
   

   # Check out the ArcGIS Spatial Analyst extension license
   arcpy.CheckOutExtension("Spatial")
   
   
   # Execute CostDistance
   outCostDistance = CostDistance("origin",SOURCE,"#","D:/RasterStuff/backlinkRaster.tif")
   
   # Execute CostPath
   outCostPath = CostPath("destination", outCostDistance,"D:/RasterStuff/backlinkRaster.tif")
   
   # Convert Result to Polyline
   arcpy.RasterToPolyline_conversion(outCostPath, "D:/RasterStuff/costPath.shp")
   featSet = arcpy.FeatureSet()
   
   featSet.load("in_memory/costPath")
   
   arcpy.SetParameter(0,featSet)
   

   
   

   except: # do stuff with error print finally: print

   
   

Answer

I found that when I reverting back to arcgisscripting (instead of arcpy), the gp service works fine...

My code in this script is pretty vanilla - scraped almost entirely from ESRI site, so I have no idea what could be causing the problem.