Your webpage says "Note that for now, it looks like you can't have two NetBSD partitions on the same drive on i386." This is unclear. I use NetBSD i386 with multiple fdisk partitions on same disk (although I only boot from one). until recently, i believe this was not well supported at all but it has been fixed recently, and i think you can boot from multiple netbsd partitions even. but that may not be in 1.6..