I am characterizing the problem, hoping to submit a bug report for Maemo.

I'm just waiting for someone to say, "Well, THAT's not a bug to be fixed, that's just your fault for inducing an unstable situation! Of COURSE that one-line text file created in your home directory, where by default there is no such text file, would alter the behaviour of one of the pieces of software present by default in your N900, so that it becomes unusable unless you reflash the firmware and eMMC!"

Bonus points if you can name the text file, and the already-present piece of software which is affected by this text file.