[Q] spatial datablade

Hi, I'm using Informix 9.2 with spatial blade (8.11.UC1). It seems that the spatial funcfion, e.g., distance, does not consider the 3rd element. The following is the script that I ran and the result of the query. ------------< script for Informix spatial datablade >-------------- create table stest (location ST_geometry); insert into stest values(ST_PointFromText('point z(3 4 10)',1)); insert into stest values (ST_PointFromText('point z(3 5 1)',1)); create index stest_idx on stest (location ST_Geometry_ops) using rtree; update statistics for table stest (location); select location, st_distance(location,st_pointfromtext('point z(3 4 0)', 1)) from stest; ## RESULT location 1 POINT Z (3 4 10) (expression) 0.00 location 1 POINT Z (3 5 1) (expression) 1.000000000000 ------------< script for Informix spatial datablade >-------------- If the 3rd element is considered, the distance between (3,4,0) and (3,5,1) should be closer than that between (3,4,0) and (3,4,10), but it seems that this is not the case for geodetic distance function. I'm wondering if this is true that the geodetic spatial functions doesn't consider the 3rd element in the point or if there is something that I'm missing here. Any comments would be appreciated. Thanks in advance, Kiyoung..