280c modem trouble

[B. Dowler]

With a lot of sweat and frustration along with some helpful hints from the
list and the archives, I have finally resurected my 280c modem to the point
where I can get a dial tone.  I have loaded Apple Telecom 2.3.3 onto system
7.5 with Free PPP.  However, even though the modem can be found and there
is a dial tone, the modem is  unrecognizable at times and is recognizable
at other times.  It will identify the modem but with different symbols in
the connection window on each connection attempt.  It will even dial up on
occasion, make a conncection, but the connection will not be stable and
e-mail access has not been achieved. Is there something else that I need to
do?  Do I need to place an init string into the PPP?  Would installing Geo
Port - EM updater 3.0 help/duty?  Perhaps a higher OS like 8.1?