I had to edit the plugin to make it work in my post bit. In most cases, if it doesn't work for you the div container that the plugin is looking to replace has a css class in it.
For example, I had to change
Code:
'#<div id=\\\"post_message_\$post\[postid\]\\\">\$post\[message\]</div>#i'
to this:
Code:
'#<div id=\\\"post_message_\$post\[postid\]\\\"
class=\\\"vb_postbit\\\">\$post\[message\]</div>#i'
in the "tDigg - Template Edits" plugin.
If you are having trouble, search your postbit template for $post[message], PM me the entire div container that $post[message] is in, and I'll reply with what you need to edit when i have a chance.