This issue seemed to be caused by insufficient power to the graphics card. I removed the card and went back to the video offered on the shuttle motherboard I use. This solved the problem with the white lines and artifacts.
NOW I have a new problem. After the loading screen at the start of a new game, or after attempting to load a saved game, GC2 seems to be about to display the galaxy screen when I get some kind of Exception Error.
I get this set of info.
AppName: galciv2.exe AppVer: 1.0.0.1 ModName: d3d9.dll
ModVer: 5.3.2600.2180 Offset: 00043f3d.
Does anyone know how to read the reams of additional info that it provides? Does anyone know how to solve my problem? I have definately GOT the d3d9.dll file, and have ensured that the dxsetup.exe from the GC2 disk2 does not add any further files to my computer.