proc signals problems

I have a multithread program that have connections at DB (ORAClE) by contexts, but my problem is when a signal ( SIGINT )arrive just in the second when the query is executing this down the process; but I have a signal_wait but this signal never is taken for the signal_wait but this not ocurr with the signal SIGTERM.

Thanks for your help

    sigemptyset(&signal_set_admanager);
    sigaddset( &signal_set_admanager, SIGINT );     sigaddset( &signal_set_admanager, SIGTERM );     pthread_sigmask( SIG_BLOCK, &signal_set_admanager, NULL );

    sigwait( &signal_set_admanager, &sig_number );                 

     printf("Cancelling threads...\n");                         

     if ( sig_number == SIGINT || sig_number == SIGTERM ){			
		cancel_threads();
		break;
		}