MicroReader requires FW49 or better for SL45i and 6688i. Determine
the firware version on your handset by pressing the keys *#06# on the phone
and then the left softkey. If the display shows Version 43 and you still
want to use MicroReader, take it to your local Siemens service center and
get an upgrade. For correct display of Arabic and Hebrew text FW52
or higher is needed. Other reasons to upgraded is a major speedup
of Java in FW52, and the fact that many other MIDlets also do not work
with older firmware.
There should be no problems with Siemens M50 except the limited storage
space.