Rasterfiles are sometimes not drawn

[Robert]

Hello,


My mapserver (V 4.2.0 on W2000) configuration causes a strange problem :
the raster files in an image catalog are sometimes drawn, sometimes not. If
there are drawn and I move the map a little bit, I get the error message :
Warning: [MapServer Error]: msDrawMap(): Failed to draw layer
named 'RasterKat'. in D:\MS_WEB\demo4.

This problem is new, I did not change anything in the mapfile or in the
catalog.

Robert