[Plugin: Simply Show IDs] categories ID ?????

This plugin will: https://www.ads-software.com/extend/plugins/reveal-ids-for-wp-admin-25/

From the info at:
https://www.ads-software.com/extend/plugins/simply-show-ids/
“Simply shows the ID of Posts, Pages, Media and Links”

This plugin has worked for me before. But the Plug 1.1.5 that I have just installed on top of WP 2.8.4 doesn’t seem to work. I’ve got all 0 IDs for pages and posts. Any idea what maybe the issue here? Thanks.