Application 'man' is installed into /sbin whereas it should be into /bin. Otherwise, only root can display man pages. This has been seen in Busybox version 1.20.1.
Fixed in git: commit 80a38ca11c3c9e0fdef07ad3fc908aa54afb4386 Author: Denys Vlasenko <vda.linux@googlemail.com> Date: Wed Mar 27 14:30:18 2013 +0100 man: install to /usr/bin, not /sbin