A while ago I found I was getting problems with $portfree on Win98 as well - IIRC it was basically only recognising whether or not ports were used by mIRC or the usual Windows services, and not correctly recognising port usage by other applications.
I'd provide more details, but this was several versions ago, and in the end I found a workaround for what I wanted to do anyway... so it had slipped from my mind until I saw this thread. (Sorry!
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