«Wake is also more common than waken when used together with up, and awake and awaken never occur in this context: She woke up (rarely wakened up; never awakened up or awoke up). »
EDIT: ...Though they claim it's The American Heritage Dictionary that the article is from...
Hmm. I don't know where exactly I got the information that only wake takes up. Apparently waken goes with up according to some sources. Personally, I only use wake with up. CJ