Problem with SMAC, MC13213 and single port

Hi,
I try to use a FREESCALE MC13213 (ZigBee) in single port mode.
I generated a CodeWarrior project with BeeKit for a NCB board (not mine ; I
use a custom board).

I read the AN3248 and changed the value of the 0x07 modem register (0x5C00
instead of 0x4C00).

My board doesn't receive or transmit anything (the same code is running well
on 13192EVB and SARD board on the same time).

Any ideas ?

Regards,
Yvan