Symbian OS cells SPP connection fail.

Hi All,

I have a big problem on Symbian OS cells SPP connection problem.
I can easily connect to cells from PC with SPP service, but except
Symbian OS cells ( NOKIA 6600, Sony Ericsson P800/P900/P910i...)

I traced some data, and I have some issue here:

For Symbian OS cells
1. Do we have to apply '4' as channel server?
2. Do we have to reject 'role switch request' ?
What's the different actions between accept or not_accept the 'role
switch request' from Symbian OS cells?
3. Do we have to setup Symbian OS modem status if we only want to use
SPP connection ?

Thank you very much for your help.
Best regards,
Boki.