dpkg error stops upgrade

[Richard Kimber <rkimber@ntlworld.com>]

In testing, after apt-get update, apt-get upgrade stops with a dpkg
error:-

Preparing to replace logtail 1.1.1-13.1 (using
..../logtail_1.1.9.1_all.deb) ...
Unpacking replacement logtail ...
dpkg: error processing /var/cache/apt/archives/logtail_1.1.9.1_all.deb
(--unpack):
 trying to overwrite `/usr/share/man/man8/logtail.8.gz', which is also in
package logcheck
Errors were encountered while processing:
 /var/cache/apt/archives/logtail_1.1.9.1_all.deb

A previous contributor suggested I should upgrade logcheck, but the error
also occurs if I try to do that.

dpkg -C shows nothing
and
dpkg -s logcheck gives
Status: install ok installed
as does
dpk -s logtail

What do I do to solve this?  Is this a bug?

Thanks,

- Richard