I jusy tested on my ageing 7650 the alternative Symnianware's screensaver (not only of the standard but also of PSINT's screensaver) named "PowerLock".
To my surprise the battery and the signal meters are the same with SX1's (and offcourse the same with every Siemens phone).
I don't know, if this means anything but can anyone say that it is illegal (Siemens registered trademarks or sth like that), or maybe a bug of the app, or nothing of the above...