eps/pdf/svg contourf contours don't overlap properly with high resolution data

I have a bug that I am seeing with a default ubuntu 9.10 matplotlib install, version 0.99.0. Contourf plots that I output in vector format files have little triangular glitches at the contour boundaries if the contoured array is larger than about 200x200. The same files in png format are perfect, even at very high dpi values. Attached is a sample script, and the png and eps output it generates on my machine. I'm trying to make eps files for a paper, and this is driving me nuts. Any ideas?

Jordan

bug.py (351 Bytes)

bug.png

bug.eps (22.5 KB)