Problem with DSP C6713

Hi,
   I hope, this is a right newsgroup for my question.

   I have a DSK with C6713 DSP. I'm sending data to McBSP by EDMA. Data 
is testing sequence, Uint8 Buffer[256]. Buffer[0] to [255] = 0xAA 
(10101010).

   Peripherial frequency is 100MHz. All is configured by DSP/BIOS Config.

   When I set McBSP Clock freq. Divider to 4 (one bit = 40ns) everything 
is OK. On DX pin is 10101010101010101010...., but when I set divider to 
2, or 1 (one bit = 20, or 10ns), data on DX pin are scrambled. 
10101010--something between log.0 and log.1--10101010--again 
something--10101010--again.....

   Thank's for help

--
MiLo