So I load a texture and create mipmaps(initially w/ my own code,later w/ gluBuild2DMipmaps for debugging purposes) and everythng looks fine until I try to set the TEXTURE_BASE_LEVEL of the texture(right after texture object creation) to some other value,say 1.Then the texture looks completely messed up.Also when I do this and do not specify the level 0 texture at all(which IIRC isn’t needed for a mipmap-complete texture if baselevel!=0) I get a driver error saying it couldn’t upload the texture.I have a G400(known for buggy drivers) under linux so I assume this is a driver bug,but just to make sure,would the above procedure work correctly w/ other drivers/cards?
It always worked out just fine for me. And that’s on ATi cards, famous for their great drivers 
So I’d say, go blame Matrox.