ash: printf problem interpreting octal escape sequences

[Alexander Kriegisch]

$ uname -a
Linux fb7270 2.6.19.2 #1 Fri Feb 24 02:09:03 CET 2012 mips GNU/Linux

$ busybox --help | head -n 1
BusyBox v1.19.4 (2012-03-01 12:42:09 CET) multi-call binary.

# Okay
$ printf "%b" '\057usr\057bin\n'
/usr/bin

# Not okay
$ printf "%b" '\0057usr\0057bin\n'
7usr7bin

Maybe somebody can fix this? If I can provide more info, please let me know.
-- 
Alexander Kriegisch