Perhaps I missed a response or two to this. In case not ...

>          If I am reading things correctly, all my v4.1 clients are NOT
> compatible with V5.1 server.  Nor is a V5.1 client (where supported)
> compatible with a V4.1.5 server.

Let's not confuse "compatible" with "supported"!   :-)

*SM has been very good in terms of old clients on old boxes still
working with new servers. I still have a bunch of version 2 clients
backing up DOS machines. Tivoli won't support that, but they also
haven't broken it.  Win95, and now Win98, are similar ... don't put the
version 5.1 client on them, but if you use what is or was once a
supported client for the operating system, you'll find they will work.

The down-level backup server is a bit more of a problem. Newer clients
tend to run, but without new function that requires backup server
support.  I don't know, but would guess that a 5.1 Windows client
backing up to your 4.1 server might have problems with the registry, as
the server has (unfortunately) some functional changes with regard to
system objects (I forget the version where this breaks (3.1/3.7/4.1)).

Hope this helps, wayne

Wayne T. Smith                          ADSM AT Maine DOT edu
ADSM Technical Coordinator - UNET       University of Maine System