Mines level all the way accross no issues. Think the later build N900s have had the issue address with the keyboard? the bottom plastic line to be fair does move but i have to purposely try and move it for it to be an issue.

Just post the link up to the spare parts ordering website on here? might be worthwhile replacing the keyboard with a new one / or frame if they are cheap.

Might be good to just have a spare anyway i see these keyboards wearing out after a few years use !