Hi, thanks for the replies!
I messed about with about every combination of package installaions I could manage, but it still wouldn't work!
I reinstalled over '/' with i586 rather than x86_64 and it worked - well it overcame the original problem I had at least (still wouldn't compile completely, but that's a story for another day!).
Phew, this learning curve is steep :D
Even so, in the past few days I've gone from being a complete Linux newbie, to having a sweet looking KDE system with faster stats than I ever had before, and I've helped a friend get Mandriva running too!