trouble shirring

[petatron.livejournal.com]

i've been trying to make a simple shirred summer dress. for some reason my fabric won't shirr. i've never shirred anything with this machine before, i've only had it for a few months.

i've tried winding the elastic on the bobbin tight and loosely, i've tried a straight stitch on the longest setting, i've been told to try a small zig zag and that didnt' work either.
i've even tried two different types of elastic thread.
it just won't shirr.

someone tell me what i'm doing wrong. or point me in the direction of something helpful. i've googled the crap out of this, and i can't find anything helpful.