Ehhh....
I unmounted a number of partitions with no userland errors...Maybe this
could be changed to indicate which partition it was? The odd part is I
killed all processes on the suspect partition and umount returned busy
however lsof indicated no files open on that partition. A third
invocation of umount got it to unmount. This was a reiserfs partition
btw. The ext2 partition is /boot and e2fsck on it didn't yield any errors.
Kernel 2.4.7, ext2 and reiserfs partitions.
David