"su: cannot run /bin/sh: Permission denied"

[Ganskow]

I have used a pre-compiled uClibc development system on i386 - all fine as 
long as I work with root on it.
In the moment i tried to switch to a user with su (adding a user and the group 
was ok, in /etc/passwd and shadow are all expected entries) the following 
message comes up: "su: cannot run /bin/sh: Permission denied". also after 
setting a /etc/shells it does not work. by the way I checked the userrights 
and they are as should in /bin/sh+bash+busybox.

what else can be done in such a case?

tks nd krgds

stefan
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