**I** didn't upgrade, the GNU community upgraded for me!
Every system is in some way fragile. WIth Linux, it's the compiler and libc installation. It should be easy to just drop in a back-dated version but it isn't - and since I DO need the C++ improvements in 3.x, I'd have that anyway - but the wankers should STOP FUCKING WITH C and ISOLATE C++ in its own buggered world.
(Anyway I found a way around the problem.)