shptreetst problems -- mapserver 4.6.2

[Warren Freitag]

Just wondering if anybody could provide some pointers for me ... it's 
quite likely I'm doing something wrong here with trying to use 
"shptreetst" (i.e. the msSearchDiskTree() function) to query a shape 
index for features in a given envelope.

I have a spatial index, us_water.qix, generated from an ESRI shapefile 
of the same name using the "shptree" tool. I know this shape file is 
accurate because it was used successfully to generate maps using both 
ArcGIS and Mapserver. However, when I run the following query:

shptreetst us_water -79.00002 38.00002 -79.00002 38.00002
(the lat/lon envelope is a point somewhere on dry land in Virginia)

it gives me the following output:

This new LSB index supports a shapefile with 107931 shapes, 15 depth
shapes 3, node 3, -179.231086,17.831509,179.859680,71.441059
shapes 16, node 4, -179.231086,17.831509,-70.606129,71.441059
shapes 11, node 4, -179.231086,17.831509,-146.372037,71.441059
shapes 0, node 1, -179.231086,17.831509,-161.158609,47.316761
shapes 0, node 1, -171.098471,17.831509,-161.158609,34.048398
shapes 0, node 2, -166.625533,17.831509,-161.158609,26.750798
shapes 0, node 1, -164.165417,21.845189,-161.158609,26.750798
shapes 0, node 1, -162.812353,21.845189,-161.158609,24.543274
shapes 0, node 1, -162.812353,21.845189,-161.902794,23.329136
shapes 0, node 1, -162.403052,22.512965,-161.902794,23.329136
shapes 0, node 1, -162.177936,22.880242,-161.902794,23.329136
shapes 0, node 1, -162.054122,22.880242,-161.902794,23.127133
shapes 0, node 1, -161.986024,22.991343,-161.902794,23.127133
shapes 0, node 1, -161.948571,22.991343,-161.902794,23.066028
shapes 1, node 0, -161.927971,23.024951,-161.902794,23.066028
shapes 0, node 1, -166.625533,21.845189,-163.618725,26.750798
shapes 0, node 1, -165.272469,21.845189,-163.618725,24.543274
shapes 0, node 1, -165.272469,23.059327,-164.362910,24.543274
shapes 0, node 1, -164.863168,23.059327,-164.362910,23.875498
shapes 0, node 1, -164.863168,23.426604,-164.588026,23.875498
read entire file now at quad box rec 20 file pos 1020
result of rectangle search was
 400, 606, 607, 2415, 2595, 2596, 4279, 4357, 4359, 4377, 4382, 4394, 
4444, 4446, 4502, 4570, 4588, 4638, 4643, 40451, 74431, 75359, 81934, 
94864, 94874, 94916, 94918, 95277, 95418, 95904, 96178, 96348, 96349, 
96350, 99862, 99944, 99955, 100015,

Now, if I read this correctly, it's telling me that this single point 
intersects with some 3 dozen bodies of water. I know that can't be the 
case! I was expecting to see no matches at all.

How do these numbers match up to shape IDs in the shapefile's 
corresponding DBF? or do they match at all?

Any help or guidance would be appreciated!!

Many thanks,
Warren