I just noticed that in the "about product" information, the model, make and everything is listed as <unknown> after installing this. Not 100% sure that fmtx-faker is at fault, but i flashed the phone clean (firmware+emmc), and did nothing else then installing fmtx-faker, and the <unknown> showed up again. Uninstalling from application manager does not fix it. Running "dpkg --purge fmtx-faker" does fix it however. Reproduced it twice.

Normally it says:
Nokia N900
Maemo 5
Version: 1.2009.42-11.203.2

With fmtx-faker installed:
<unknown>
<unknown>
Version: <unknown>

Even though it looks like this, the phone works and performs normally, so I guess it's just cosmetic stuff. However I guess it qualifies as a bug.

edit: only tested with the fmtx-faker version from extras-dev, i believe it's version 0.2