> I am wondering why certain web sites do not "remember me" (including
> this one)
Aside: this is not a Web site. This is Usenet (aka "newsgroups"). Some,
like Google, offer some form of access to it through a Web site. But
that's just your choice of how to access Usenet. Usenet itself is not
part of the Web.
> consistently even though I have my browser set to accept
> cookies.
Depends on the site. Each site will use its own implementation. Welcome
to the World Wild Web.
> Do they expire?
They can and most probably do, yes, but after how long depends on the
site.
> What happens if I access a site and log in
> from a different computer?
Depends on the site.
> Will that void the "remembering" on the
> original machine?
Depends on the site.
> Is it affected by software or operating system
> version?
Only if the site sniffs for such info and lets it play a role.

Signature
Sander Tekelenburg, <http://www.euronet.nl/~tekelenb/>
Mac user: "Macs only have 40 viruses, tops!"
PC user: "SEE! Not even the virus writers support Macs!"