Re: SSI bug?

I wrote:

> it seems likely that such a cycle might be related to this new
> code not properly allowing for some aspect of tuple cleanup.

I found a couple places where cleanup could let these fall through
the cracks long enough to get stale and still be around when a tuple
ID is re-used, causing problems.  Please try the attached patch and
see if it fixes the problem for you.

If it does, then there's no need to try to track the other things I
was asking about.

Thanks!

-Kevin