SHAPEPATH misbehavior with grids? Windows<->Mac OS X

[Jeroen Ticheler]

Dear people,
We are seeing different behavior of MapServer 4.6 on Windows and Mac  
OS X.

On Windows the SHAPEPATH value seems to be ignored for ESRI-grids  
(not sure about other image formats, although I think the same  
applied for GeoTIFF). When we specify the full path in the DATA  
element of a LAYER it works fine.

On Mac OS X the SHAPEPATH value is used and only the name of the  
dataset needs to be set in the DATA element of the LAYER

Is there a reason for this inconsistency?
Thanks in advance!
Jeroen