no audio w. Messenger

haven't been to TSG since april- that's a good thing, i guess.
anyhow, i finally need help again- i recently bought a cheap webcam made by creative, that came with a mike, to use with my IM-ing (msn). but my firewall seems to be blocking the audio from working. i am using the free version of zonealarm. (OS is win2k). i made a couple of feeble attempts to lower my security settings, but am not comfortable with it, and the little i did do has not changed the audio issue.
i'm hoping there is a simple, step-by-step way to modify my settings (or my firewall) to allow audio that one of you is just dying to walk me through.
i've done all the proper setup stuff, by the way, and the test to determine the mike itself is working, etc. it's all good that way. but every time i try to activate the audio part of the conversation, a ZA firewall alert comes up.
thanks in advance for the incredible help i always get from this site.

mezz