Ftp cache time

I'm curious about squid and the length of time which netscapes ftp site
stays in my cache. My max. object size is set to 20 meg and I have about
8 gig free on the cache drive. If I go to ftp.netscape.com and download
netscape gold v3.03 (for example) it only seems to hold it and the ftp
directory listings for about 2 weeks before they get ejected. It's
nothing to do with ftp.netscape.com changing IP addresses either as they
changed in the last few days and my cache still held the info.
the access log didn't seem to indicate anything helpful (to me anyway).

using squid novm 15 on linux and ftp files from other sites (although
those sites use an HTML interface) seem to stay in the cache for ages...

if anyone has any ideas, I'd like to know.
thanks,
craig heading.

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