Cannot Modify Custom Shortcode

I’ve set up a custom shortcode that allows you to run a custom query from within a Text Widget.

The following tutorials allowed me to do so:
http://digwp.com/2010/03/shortcodes-in-widgets/
http://digwp.com/2010/01/custom-query-shortcode/

I got things working pretty well, and just as I was about to really customize the output (to include custom meta), suddenly no changes I make to the shortcode code will affect the output. I can’t even break it.

Does anyone have any advice for me? Thanks!