Gros problèmes en configurer le microphone

Bonjour,
Je suis sous Kubuntu 7.10, et je trouve des problèmes sérieux avec mon microphone... le son marche très bien, les headphones aussi, mais j'essaye d'utiliser un 'headset' avec un mic, et le mic ne marche pas du tout... je crois qu'il y a un conflit avec quelque chose d'autre, parce que, chaque fois que j'essaye de le tester avec Ekiga, Skype or Audacity, le programme simplement cesse de répondre tout de suite.
J'ai besoin d'aide, je ne sais plus quoi faire... et j'ai vraiment besoin d'utiliser un programme de téléphone sur l'internet pour parler à mon pays.
Si quelqu'un a une idée de ce qui se passe, voici mes spécifications d'audio:

Audio device: ATI Technologies Inc SB450 HDA Audio (rev 01)

*-multimedia
description: Audio device
product: SB450 HDA Audio
vendor: ATI Technologies Inc
physical id: 14.2
bus info: pci@0000:00:14.2
version: 01
width: 64 bits
clock: 33MHz
capabilities: bus_master cap_list
configuration: driver=HDA Intel latency=64 module=snd_hda_intel

Et peut-être si c'est aussi utile, les spécifications d'input:
amixer:
Simple mixer control 'Headphone',0
Capabilities: pswitch
Playback channels: Front Left - Front Right
Mono:
Front Left: Playback [on]
Front Right: Playback [on]
Simple mixer control 'PCM',0
Capabilities: pvolume
Playback channels: Front Left - Front Right
Limits: Playback 0 - 255
Mono:
Front Left: Playback 255 [100%] [0.00dB]
Front Right: Playback 255 [100%] [0.00dB]
Simple mixer control 'Front',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 23 [74%] [-12.00dB] [on]
Front Right: Playback 23 [74%] [-12.00dB] [on]
Simple mixer control 'Front Mic',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 15 [48%] [-12.00dB] [on]
Front Right: Playback 15 [48%] [-12.00dB] [on]
Simple mixer control 'Front Mic Boost',0
Capabilities: volume
Playback channels: Front Left - Front Right
Capture channels: Front Left - Front Right
Limits: 0 - 3
Front Left: 0 [0%]
Front Right: 0 [0%]
Simple mixer control 'Surround',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 0 [0%] [-46.50dB] [off]
Front Right: Playback 0 [0%] [-46.50dB] [off]
Simple mixer control 'Center',0
Capabilities: pvolume pvolume-joined pswitch pswitch-joined
Playback channels: Mono
Limits: Playback 0 - 31
Mono: Playback 0 [0%] [-46.50dB] [off]
Simple mixer control 'LFE',0
Capabilities: pvolume pvolume-joined pswitch pswitch-joined
Playback channels: Mono
Limits: Playback 0 - 31
Mono: Playback 0 [0%] [-46.50dB] [off]
Simple mixer control 'Side',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 0 [0%] [-46.50dB] [off]
Front Right: Playback 0 [0%] [-46.50dB] [off]
Simple mixer control 'Line',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 0 [0%] [-34.50dB] [off]
Front Right: Playback 0 [0%] [-34.50dB] [off]
Simple mixer control 'CD',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 0 [0%] [-34.50dB] [off]
Front Right: Playback 0 [0%] [-34.50dB] [off]
Simple mixer control 'Mic',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 0 [0%] [-34.50dB] [off]
Front Right: Playback 0 [0%] [-34.50dB] [off]
Simple mixer control 'Mic Boost',0
Capabilities: volume
Playback channels: Front Left - Front Right
Capture channels: Front Left - Front Right
Limits: 0 - 3
Front Left: 0 [0%]
Front Right: 0 [0%]
Simple mixer control 'PC Speaker',0
Capabilities: pvolume pswitch
Playback channels: Front Left - Front Right
Limits: Playback 0 - 31
Mono:
Front Left: Playback 0 [0%] [-34.50dB] [off]
Front Right: Playback 0 [0%] [-34.50dB] [off]
Simple mixer control 'Capture',0
Capabilities: cvolume cswitch
Capture channels: Front Left - Front Right
Limits: Capture 0 - 31
Front Left: Capture 31 [100%] [34.50dB] [off]
Front Right: Capture 31 [100%] [34.50dB] [off]
Simple mixer control 'Capture',1
Capabilities: cvolume cswitch
Capture channels: Front Left - Front Right
Limits: Capture 0 - 31
Front Left: Capture 0 [0%] [-12.00dB] [off]
Front Right: Capture 0 [0%] [-12.00dB] [off]
Simple mixer control 'Channel Mode',0
Capabilities: enum
Items: '2ch'
Item0: '2ch'
Simple mixer control 'Digital',0
Capabilities: cvolume
Capture channels: Front Left - Front Right
Limits: Capture 0 - 120
Front Left: Capture 60 [50%] [0.00dB]
Front Right: Capture 60 [50%] [0.00dB]
Simple mixer control 'Input Source',0
Capabilities: enum
Items: 'Mic' 'Front Mic' 'Line' 'CD'
Item0: 'Front Mic'
Simple mixer control 'Input Source',1
Capabilities: enum
Items: 'Mic' 'Front Mic' 'Line' 'CD'
Item0: 'Mic'

Merci beaucoup!!