idmap_ldap + idmap_tdb are no longer statically built in by default reproduce: start winbind with minimal idmap configuration (idmap uid and idmap gid), call wbinfo --allocate-uid, --allocate-gid.
It turns out that the initialization function for the builtin-by-default backends was not called at the right time. http://gitweb.samba.org/?p=samba.git;a=commitdiff;h=a552aa1c3f67b76692e26a5560640dcfae0831b6 fixes it for me.
Ok, I'm not closing this myself without having someone having put up testresults in here. This is critical :)
After applying the patch, wbinfo --allocate-uid and --allocate-gid both work for me.
I think this one is fixed in Samba 3.3.4. Please re-open if it's still an issue. Closing out bug report.
*** Bug 6141 has been marked as a duplicate of this bug. ***