[BusyBox] backref problem with sed?

[Bene, Martin]

Hi, I get the following effect:

# echo "BOOT_IMAGE=vmlinuz root=/dev/hda5 initrd=init1" | ./sed -e
's/.*root=/\1/'
u/dev/hda5 initrd=init1

The leading "u" character comes from the "vmlinuz" string, but what is it
doing in the output? Either I'm doing something stupid or there's a bug;
standard sed works as expected.

Bye, Martin