I know, i'm very late on the upgrade of this plugin, i'm very sorry.
I'm sorry, may be i'm too in the next release to figure out what you are saying.
As far as i can remember, there is (and really soon was) 2 kinds of way to add snippets :
1/ using the Group Snippets component (and then you can eventually use a shortcode to retrieve the content in forums or posts such as [snippet id="1"]
2/ directly adding content in forum or posts thanks to a thickbox that actually write the content in forums sql table or posts sql table.
Now all the content you created with 1st method, even if the plugin is deactivated or deleted is still in a [table_prefix]code_snippets and comments in [table_prefix]code_snippets_comments. And this because i didnt add an uninstall.php script.
Now, if you look at the link you first gave me, i just checked : the content is still there !!!! (but without code highlighting...)
I've noticed that you didn't apply the patch i gave you on this reply
Now, let's think about the future !
I'm finishing BP Code Snippets version 2.0. It should be in repository very soon. I just need to take care at the previous versions generated content (as you asked me to).
This was the first plugin i submitted to WordPress repo, since then i've learnt a lot, and the next release has completely changed the way of managing the content.
So, i strongly recommand you when it will come to upgrade the plugin to make a back up the 2 tables the plugin created :
The main trouble will be for the content written using the 2nd method...
Have a nice day.