Comment 8 for bug 327174

OK, it would appear that /usr/bin/labyrinth uses "site-packages" in its path definition rather than "dist-packages"; in other words, correcting only the version number (from 2.5 to 2.6) is not enough. Make sure the line looks exactly as shown in comment 6.
Once this error was corrected, I had no more problems except it now could not locate Numeric - but then that was easily solved by installing python-numeric.