For tutorials for blender 2.48:
The machinimatrix tutorials are made with blender 2.46, 2.47 and the last one is made with 2.48a. Everything we tell is valid for blender-2.48.
For your first question:
You can find the VCOL Paint button in the shading environment (F5) and there in the Material buttons section (the red sphere icon right to the light bulb icon)
For your secnd question:
Do you refer to your earlier question on the machinimatrix-blog ?
If so, then maybe you are not Warping to 360 degrees but a little less or more? DO you warp with the mouse or by typing in 360 on the keybard ? When you zoom into the seam, can you see the vertices beeing separated or are they truly laying on each other ? Remove doubles only works when vertices are very close to each other. I am not sure but i think you can define what "near" means exactly on blenders system info screen.
The technique shown in the tutorial is definitely working with blender 2.48 And we even have found a bug in the UV-unwrapper of blender-2.47 while we where creating the tutorial, which stopped me from showing multires in the given context.
The bug has been fixed very quickly in blender-2.48 (Kudos to the blender developers

As soon as we get informed that the machinimatrix-tutorials have become incompatible to the up to date blender, we will update the content as soon as possible.
I hope that helps a bit ?
Otherwise can you describe in more detail, what your problem is ?