AAACKK - I spoke too soon. This is with 00005.patch backed out. If I use 00005.patch the same problem occurs.
I'd like to report that the problem I encountered with 2.5.50-dm-2 ( on LV not mounted, ioctl error) has been fixed in 2.5.51-dm-1. I can now get all my LVs with it.
Thanks Joe, whatever you did works a charm.
Regards Richard