DQPSK Mod/Demod and Garbled Text

In GRC I’m setting up a flow graph to modulate and demodulate a text
file (simulation and without the USRP). DBPSK and D8PSK runs just fine
,
however with DQPSK I get the text but it is garbled in places? Since
it’s
the same flow graphs, with the only differnece being menu picks in the
mod
and demod blocks, could this be a bug?

Also…I’m doing the same thing for BPSK and was wondering if I can
use
the Packet encoder and decoder with the MPSK reciever? If so, how do I
do the type conversion from complex to byte?

Cheers,
Jody