It might very well have been DMI, on reflection (had to disassemble the kit
due to visitors - will get another chance at it all sometime on Sunday),
however this is not something I'm concerned about as (a) it's a startup
message I see on an awful lot of machines - seems pretty much par for the
course, and (b) I wasn't seeing any problems booting XP-based disks, just
Linux ones, although these appear to be quite happy now - thought it might
have been a firmware issue (even bought a new DVD drive, just in case that
was the problem (I'd tried a couple of old CD drives, with the same
result)), or a combination of the actual hardware/firmware revisions, but
everything suddenly started working ok (albeit with the new DVD drive, but
not immediately after I'd installed it) - I guess something simply needed
settling in - I know from bitter experience just how awkward these things
can be when they feel like it .... I've built/rebuilt enough of the things
over the years to find that out ...