Reprojected ghost images

[John Westwood]

Hello fellow MapServer users,
 
I have a small problem with reprojecting a tileindexed raster layer.
The original layer is in GB National Grid coordinates and I have
reprojected this on the fly to latitude and longitude. The coverage of
the layer extends to the area of the United Kingdom. The re-projection
works fine and I am very happy with it.
 
The problem is if I zoom out to a whole World view, there are two
duplicates of the reprojected UK raster layer equally spaced on either
side of the real layer. The duplicates are on the same line of latitude
as the real layer but are approximately located in North America and
East Russia. The duplicates are also heavily distorted, and one is the
mirror image of the other.
 
I would like to know what is causing this and how I can possibly
prevent it. I have a workaround which is to switch the layer off when I
have zoomed out a certain amount; this works ok at the moment but may
cause problems in the future. Any ideas would be greatly appreciated. I
am using MapServer version 4.10.0-5+etch1 on Debian Etch.
 
Regards,
 
John W.
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