I think what he’s saying is that when he tries to disable integration, he can no longer access SMF’s login at all.
Here’s a post that’ll help, I hope:
http://modxcms.com/forums/index.php/topic,3565.msg27286.html#msg27286
Essentially, there’s a couple of SMF database entries that, if you clear ’em out, it’ll return to it’s normal state and no longer try to hook into MODx.
I’ve been away, so I haven’t been able to make any progress on my "reverse-bridge" ideas, though I converted over to SMF a little while ago (PHPBB was getting impossible to manage all the spam signups). So thus far, no progress in getting my users set up to publish real articles to the "main" site yet.
But now there’s a G2 plugin, so I’ve got to play w/ that as well (and get the heck off of Coppermine!)