[AS3]Array.sortOn not accurate?

[Fall_X]

Ok, here's some code I used :

var transformedSurfaces:Array=surfaces.sortOn("depth",Array.DESCENDING|Array.NUMERIC);
for(var i:int=0;i<transformedSurfaces.length;i++) {
	trace(transformedSurfaces[i].depth);
}

And this is the result I got :

205.44603367212753
182.78833899621128
160.130644320295
138.99973123326004
138.99973123326004
138.99973123326004
138.99973123326004
138.99973123326004
138.99973123326004
114.81525496846251
114.81525496846251
114.81525496846251
92.15756029254628
92.15756029254628
90.63077870366499
90.63077870366499
90.63077870366499
73.72604823403702
69.49986561663002
48.368952529595056
48.36895252959505
48.36895252959505
48.36895252959505
37.47373675257102
37.47373675257102
30.242796788862044
30.242796788862044
24.18447626479752
24.18447626479752
1.5267815888812777
0
0
0
0
0
-24.184476264797524
-24.184476264797524
-24.184476264797524
-42.26182617406994
-42.26182617406994
-46.84217094071377
-48.36895252959505
-48.36895252959505
-48.36895252959505
0
-82.178413468851
-82.178413468851
-82.178413468851
-2.5357095704441965
-8.452365234813989
-89.10399711478371
-90.63077870366499
-90.63077870366499
-21.130913087034973
-31.696369630552457
-132.89260487773493
-132.89260487773493
-137.47294964437876
-138.99973123326006
-138.99973123326006
-138.99973123326006
-157.07708114253245
-172.80919217251602
-172.80919217251602
-172.80919217251602
-181.26155740733
-181.26155740733
-181.26155740733
-205.44603367212753
-223.52338358139994
-228.10372834804377
-263.43997087618095
-263.43997087618095
-263.43997087618095
-271.89233611099496
-271.89233611099496
-271.89233611099496
-314.15416228506496
-362.52311481465995
-362.52311481465995
-362.52311481465995
-362.52311481465995
-362.52311481465995
-362.52311481465995
-404.7849409887299
-495.41571969239493
-495.41571969239493
-495.41571969239493
-495.41571969239493
-495.41571969239493
-495.41571969239493
-495.41571969239493

Note that there's a zero out of place.

I also tried a simple Array.sort(Array.DESCENDING|Array.NUMERIC), and had the toString() function of my objects return the depth field, and that way it was accurate but a lot slower.

So, any ideas?

Thanks.