I had a problem a bit like this with my Newton. What would actually happen is that the settings would drift over time. Some patient with the notepad in drawing mode* and the alignment settings would make it right, but like I said, it drifted. I eventually discovered it was battery related; as they got flatter, the alignment would drift faster. :-)
Wade.
* That's something I miss on my Visor. I should go find a sketch pad app...