6.57 firmware is unable to read a phonebook entry

[Erwan]

hello,
on software 657_09gg.Q2406B 1954500 102706 18:44, running on a Q2406 module, in TCP client mode, with GPRS bearer.

It seems that the module is unable to read a phonebook entry :

with Firmware 6.41 :

AT+CPBR=1,1 <---- AT command sent to the module

RX 10=AA 02 E8 0D 0A AB AA 29 E8 2B <----answer from the module

STR: RX 10=43 50 42 52 3A 20 31 2C 22 2B <---- the contact is sent
STR: RX 10=33 33 31 34 38 30 33 37 33 33
STR: RX 4=36 22 2C 31
STR: RX 6=34 35 2C 22 54 65
STR: RX 10=73 74 20 50 75 73 68 22 0D 0A

+CPBR: 1,“+33148037336”,145,“Test Push”
//the contact is received

with Firmware 6.57:

AT+CPBR=1,1 <---- AT command sent to the module
STR: RX 1=8C <---- what does this mean ??
STR: RX 1=8C <----what does this mean ??
STR: RX 1=8C <----what does this mean ??

//after this command, all the other AT commands get this kind of answer:
AT+CGATT=? <-----example of command following a AT+CPBR
STR: RX 10=FA FD FB F8 F8 FF F9 FA FC FD <---- what does this mean ??
STR: RX 10=FB F9 FB FA FF FE F9 FA FC FD<---- what does this mean ??
STR: RX 9=FC FD FD FA FA FB FA FE FF<---- what does this mean ??

Do you know if this will be corrected on the last release of the firmware ?
Regards.