Cron fail caused by orphaned action?

I just got through a day of troubleshooting why cron wouldn't run on Drupal 6.13 (would either fail or tell me cron was already running), and wsod when running a status report. I'm assuming this was the cause:
- One orphaned action (comment_unpublish_action)

I only got the above log message after disabling all modules except database logging and core required. Choosing "removed orphaned actions" I was again able to run cron manually.

Before this I went through all the steps suggested in other posts without success or insight (i.e. removing the cron items from the variables table; clearing cache; also modifying module.inc with a line to include cron in the watchdog table).

I'm really not sure what caused the problem in the first place, but it did occur days after upgrading to 6.13 and specifically when I tried adding the emfield module. The module installation failed with a wsod, but I know other people are using it with success so the issue may've started before that. Only other thing I can remember changing was installing the dev version of Administration menu since the current one wasn't compatible with 6.13.

I'm still not sure what the culprit is. The comment_unpublish_action makes little sense to me because all of my content types have comments disabled.

If anyone has insight I'd appreciate it. Thanks.