TMS320F28335 CANB can not transmit any frame of data,

Hello,

I have CCSR 4.x and own  tms320F28335 based card.  Board IO, SCIs properties are working very well. I started to use CANA and CANB modules. For this, We connected CANA and CanB over  CANBUS transceivers and 120 Ohm terminating resistors. For software this I used TI's original "ecan_a_to_b_xmit" example. Yes it works  for CANA  I could  i see all of frame bits  on the line via Oscilascope and on pc  screen via USB to CANII int. inaterface adapter from IXXAT, As a next step i started to test CANB trasmitting instead of CANA ( i have just changed Cana...  into Canb...) but programme loops forever at 

       do
        {
          ECanbShadow.CANTA.all = ECanbRegs.CANTA.all;
        } while(ECanbShadow.CANTA.bit.TA25 == 0 );   // Wait for TA5 bit to be set..

Crystal freq: 23.9999 Mhz,,PLL 10, CANA.GPIO 30, 31  CANB: GPIO, 8,10

I did not change any settings i have just used "ecan_a_to_b_xmit"  examle code as is. I have checked "InitECanGpio();" and    "InitECan();"

There must be some magic for that CANB that i am not aware of that. I am sure CANB transcievers are OK, I measure signals from MCU pins. What is the reason of that CANB module's unexpected behaviour? Did anybody use that example for CANB to send any frame of data to CANA, and did it really work?

At the end my purpose is to develope a code one mini client-server programme between CANA-CANB. 

Thanks in advance,

IM