Freecorder records my voice, but other voice faintly

[imagethis]

Hi,
I am running Windows XP, and have been able to record my side of an Yahoo IM conversation but the other person is very faint. I've had this same problem using other VOIP software and still haven't gotten an answer about why the other person sounds so faint. One time using audacity software their voice suddenly came thru loud, so I'm wondering if it's their mic, but never could duplicate it again. Anyway, was hoping the Freecorder would work (have now tried at least 5-6 apps to record VOIP conversations), to no avail. I am trying to do an important interview and absolutely need a good clear sound from the other part, not a faint far away sound. Any suggestions as to what I could do at my end to up the volume of the other person? My voice is loud and strong, perfectly clear, etc. Thanks for any info, I'm totally frustrated!