I put my app online back in April, during the last window, but now I'm unable to update my hours or even look at my app. Anyone else having this problem?

As long as it's "on file" for this calendar year, you can't update it unless it changes to "Active" status. Been that way since Jan 07. Subject to change as the website/app is modified. Lots of past threads on the subjetc. You can probably only put in a Resume when it's "Active" so it may behoove you to hit an AIRINC conference or work it to get HR your resume otherwise.