Not all audio programs work with an audio card

My laptop Asus A6Vm has the audio card
0000:00:1b.0 Audio device: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller (rev 04)
that doesn't woks alwais fine.
I insert the module snd_hda_intel in the blasklist.

I have and external audio card:
Bus 002 Device 002: ID 041e:3010 Creative Technology, Ltd SoundBlaster MP3+
that seems to works fine.
With kaffeine and amarok the audio is cool, with mplayer and noautn there's no sound.

I though that was samethin impossibile: if the driver works it should do for all the programs.

Any suggestion?

sirio81@1[~]$ lsmod | grep snd
snd_pcm_oss 37408 0
snd_mixer_oss 14336 1 snd_pcm_oss
snd_usb_audio 70624 2
snd_pcm 62856 2 snd_pcm_oss,snd_usb_audio
snd_timer 18308 1 snd_pcm
snd_page_alloc 7560 1 snd_pcm
snd_usb_lib 13056 1 snd_usb_audio
snd_rawmidi 17952 1 snd_usb_lib
snd_seq_device 6412 1 snd_rawmidi
snd_hwdep 6788 1 snd_usb_audio
snd 45928 13 snd_pcm_oss,snd_mixer_oss,snd_usb_audio,snd_pcm,snd_timer,snd_usb_lib,snd_rawmidi,snd_seq_device,snd_hwdep
soundcore 7008 1 snd