Cross posting into this thread as it' more appropriate...
As I understand it Blue & Me is based on Windows Mobile so I've just done some testing on my T-Mobile MDA Vario II with the recent (for T mobile) Windows Mobile 6 upgrade.
I can report that both versions of M4A play correctly on it

so there may be a fair chance provided the Blue & Me media player is the same.
For the record

the tracks were Remember Me - British Sea Power (ripped) and Love Me Like You - Magic Numbers.
Now all I need is a Windows Mobile 500





:absolutely furious emoticon:
Regards,
Tony.