No features detected using PostGIS-backed vector provider

[alalonde]

Pulling from a table with a few MultiPolygon geometries, no features seem to be detected no matter the zoom level or x y positions.

print "pre-filter features: %i projection: %s" % (layer.GetFeatureCount(), projection,) 
# 
# Spatially filter the layer 
# 
bbox = _tile_perimeter_geom(coord, projection, clipped == 'padded') 
bbox.TransformTo(layer_sref) 
layer.SetSpatialFilter(bbox) 
print "post-filter features: %i" % (layer.GetFeatureCount(),) 

which shows 2245 features before filtering, and 0 after.

Configuration: https://gist.github.com/2650080
PostGIS table is using the 900913 SRID with the definition provided here: http://tilestache.org/doc/TileStache.Vector.html

Turns out that
layer.SetSpatialFilter(bbox)
is filtering out everything, because the problem disappears when I comment it out.