Audio & Voice Settings - WinXP

[#1]

I think I have a problem with the use of an SB-Audigy card running on my PC -the MoBo of the PC has already an "embedded" Realtek sound HW.
The problem has been detected when using Skype: my voice is either stuttering -the best- or -the worst- PC crashes if in parallel of using Skype I am streaming music using IE or FireFox.
In Windows audio setting there are 2 tabs: one for voice and one for audio.
If I use the RealTek for both of them, everything is fine. If I use the Realtek for audio and the SB-Audigy for voice, I get a "metallic" voice when using Skype but remains OK overall. If I use SB-AUdigy for audio, whatever is used for voice, I get the above mentioned problem.
I'd like to get further details re. these audio/voice settings: anybody has a good URL to direct me to?
And any good recommendation besides binning the SB-Audigy card?
Patrice
Note: I have a WinXP SP2 PC, all the drivers are up to date, Skype and other SW are up to date.

[#2]

Several users on this topic in the Skype forum seem to suggest it might be related to using the latest (3.2) version of Skype and to downgrade.
http://forum.skype.com/index.php?showtopic=88328
There are other suggestions to be made, as in this thread
http://forum.skype.com/index.php?showtopic=27990
Hope it gives you some other options to investigate.

[#3]

Thanks for the reply.
I already dealt with the port forward settings.
I have thanks to your leads made a change re. hardware acceleration in the DX diagnosis tool: I'll have to test it over a period of time before considering it's fine.
Any idea where I could find detailed information re. the Sound/Audio settings tabs from control panel?
Patrice

[#4]

Hi sorry if I jump this topic but I have a sound problem with my laptop,its a Acer Travelmate 4050 series,the problem is the microphone does not work,I have been through all the settings in windows,and all appear OK when compared to my desktop,but there is no sound input at all,even useing windows recorder.Any help please.