I have a Gigabyte F2A75M-HD2 motherboard with a Realtek HD Audio chipset, and an Acteck USB webcam with a microphone that goes to the standard microphone jack. Using the microphone on just about any program shows Windows is picking the microphone audio just fine, and I can hear myself just fine if I right click the volume control, click Recording devices, double click my microphone and route its input to my audio output. However, Skype registers my microphone input at such a low volume, that other people cannot even listen to me. This happened while I was in the middle of a call since yesterday: people could hear me loud and clear, then all of a sudden they stopped hearing me.
I already configured Skype to not change automatically the microphone volume and it still will record at a low volume. I tried this fix for Realtek HD Audio, and while my microphone volume on Skype did improve a little, it is still too little to be heard by others. I tried disabling all my input jacks except the one where I have my webcam's microphone input and Skype is still recording at a low volume.