Non-ordinary command ATE0V1+CREG not working as expected?

Dear fellows,
I am trying to add connectivity to an old data-logger using WAVECOM FASTRACK Supereme 20. the problem occurs when the data logger requests the command:
the modem response with (mode 2)
+CREG: 2,1,“2EE4”,“2EE2”
although the modem is already in (mode 0); the command AT+CREG? always reported as +CREG: 0,1.
I tried the command
but it works for a few moments and rolls back to mode (2) also this setting cannot be saved with “AT&W” command.
I have to mention that the command ATE0V1+CREG? work fine with and older version of WAVECOM (657_09gg.Q24PL001 1954500 102706 18:44) and its treated as the ordinary command (AT+CREG?);

the modem information is:
Sierra Wireless
Q2687RD Product
R7.51.0.201205311751.Q2687RD 620780 053112 17:51

any suggestion would be great appreciated. thank you in advance.