I am a big fan of Microsoft OneNote, and I am using OneNote for iPad, but I was experiencing frequent crashes of the iPad application.
Some tests and some searches later, I learned that I was not alone, and that the crashes are caused by OneNote pages that contain a table with meeting information (when you create a new Linked Meeting Note from an appointment in an Outlook calendar item). So try to avoid that, or remove the table from the note if you are syncing with iPad.
![onenote table](http://www.mylearning.be/wp-content/uploads/2012/11/onenote-table.png)
Update: Microsoft updated OneNote for iPhone/iPad on July 1, 2013, and this update fixes this issue !