sms receiving doesn't work ?! why ? (nokia6600 and c++ symbian 7.0 sdk)

hi all

i'm a newbie in c++ symbian programming.

my goal is to create a .exe on my kokia 6600 (with a continuously running thread)which can react and do things when i new sms goes into my inbox. but there's a problem during the creation of my CMsvSession (during execution, not compilation) , which blocks all my program... :(

my class implements MMsvSession Observer and has this in the private section in header file :

************************************************
// header...

private :

void HandleSessionEventL(TMsvSessionEvent an_event,TAny* arg1,TAny* arg2,TAny* arg3);
CMsvSession* my_session;
CBaseMtm* my_mtm;
CClientMtmRegistry* my_registry;
**************************************************

in the ConstructL method implementation of my object :

**************************************************
// in the ConstructL ...

my_session = CMsvSession::OpenSyncL(*this);
my_registry = CClientMtmRegistry::NewL(*my_session);

**************************************************

and the bug seems to come from the construct method (i monitored with a feedback from the console...)

I saw many post in this forum, but it still don"t work :((

please some help or explanations are welcome !

thx in advance