I have seen this same type of problem, though not with the frequency
that you report. I have generally chalked it up to twitchy fingers.
We are running the same OS and LISTSERV release level.

On Mon, 17 Apr 2000, Roger Fajman <[log in to unmask]> wrote:
>
> Has anyone else encountered complaints from users about confirmation
> URLs not working that can't be explained by them expiring or having
> been done twice by the user?  The user is told that the confirmation
> number is not valid, but the command is, in fact, confirmed.  The
> LISTSERV log shows two confirmations, one right after the other.  The
> user gets only the error message from the second.  We can't reproduce
> the problem, but it seems to occur every several days.  I have actually
> seen it happen myself.  We are running LISTSERV 1.8d on Solaris 2.6.
>

--
Paul Russell
Senior Systems Administrator
Univesity of Notre Dame
http://www.nd.edu/~prussell