two way bluetooth problem

I’m working on what should be a simple problem. I have two arduino megas, one with hc-05, other with hc-06. When I send a message from the hc-06, the rx led on the attached arduino lights up, the tx led on the other arduino lights up, and the message is displayed on the com window of the other arduino (with the hc-05). Now when I try to send a message back, the leds indicate accordingly but the message is not properly received/displayed on the other com window (if i send short strings, nothing appears, long strings give me weird characters). The devices are paired properly, baud rate on both is 9600.

com4, arduino mega, hc-05, receives messages from hc-06 but has problem in transmitting
com3, arduino mega, hc-06, transmits messages to hc-05 but has problem receiving

As I said the arduinos tx/rx leds indicate communication, but somewhere is a problem.

Skeleton code:

void setup()
Serial.begin(9600); //com
Serial1.begin(9600); //bt

void loop()
if (Serial1.available())
if (Serial.available())

To follow up I swapped the hc-06 for another hc-05, set the role to 0, completed the link, and it works fine. Still doesnt answer the question of why it didnt work with the hc-06 tho.