If caching is turned on (either server or Yii) it could be the problem. Not sure how to clear it.
If you were to upload the same code again, do you get the same errors? Is it ALL other actions, or just new ones?
Not sure if I can help, but giving ideas of what to look for. I think if errors return after upload then it could be a caching problem. The other question was if you added actions and they didn’t work, but old ones did (or you got the ‘old’ data) it might point to a caching problem too.