Track.get_analysis() failure

I'm working with pyechonest and I'm trying to use the the get_analysis() method, but it never returns successfully. The minimum code to reproduce my problem is:

from pyechonest import config, track
    config.ECHO _NEST _API _KEY='my key in here'
    t = track.track _from _id('TRJSEBQ1390EC0B548')
    t.get _analysis()

(sorry about the spaces before the underscores, otherwise they show up as &#95)

Which returns:

Exception: Failed to create track analysis.

I've tried this with a number of different track ID's, and have gotten the same result every time. Any suggestions about how to solve this problem?