content_lock shown as "missing"

I installed content_lock yesterday, and tested several times. Worked as desired (except for the navigate away bug). This morning it was also working fine. Just a few minutes ago I went to install another module, remember values, and when I was attempting to enable that module, drupal told me that content_lock was missing, and I would have to disable it to proceed.

Earlier in the day I had manually patched the content_lock.module file to correct the navigate away bug, and all was working well until I attempted this unrelated module installation.

So, I attempted to uninstall content_lock using uninstall under the modules section. No error messages were given, and content lock no longer appears in the module list. So, I attempted to re-install, but when I try drupal tells me it's already installed. I even deleted the content_lock folder under sites/all/modules, still won't let me reinstall. I even flushed all caches and performed database updates, still no change.

I went into PHPMyAdmin and content_lock doesn't appear in the system table. I'm at a loss.

Any ideas?