Unfortunately, I don't have any other machines to try, so will have to let you do this one!
It would seem to me that perhaps something has been broken in the e100 module for the pxe boot? We are both experiencing exactly the same error here, so I don't think it can be a hardware problem (at least not as in faulty hardware).
If anyone knows how to rebuild the pxe kernel, I can give that a shot, but otherwise....