Thanks for replying! I'm quite new at this (and more than a bit lost here)
I'd just uploaded the .ssi page, linked index.html to point to it, and uploaded. When that didn't work I created an shtml page, re-coded the index page to point to it and uploaded that. That worked on GoDaddy's severs with another site of mine with no problem, but this one's hosted by Earthlink, and they support SSI.
Hope this makes sense, and thanks again!