Bingo. Size of std::map has changed in VS 2008 Express.
I think the only way to go with VS 2008 would be to compile Panda3D, and then link against the self-compiled libs. I have chosen to go the other way. VS 2008 Express is uninstalled, and VS 2005 Express is back again. The only difference is that I am still using the new Windows SDK (replaces Platform SDK).
First tests have been successful. Thank you for your help.
enn0x