From the ls, it looks like you have ACLs enabled on those objects (the + after the permissions). Maybe the ACL is denying permission to specific users or groups that don't appear in the ls -alh.
Adding the -e to ls should show the ACL for each object. It would show something like:
drwxr-xr-x+ 6 user group 204B Aug 25 2009 tmp
0: group:everyone deny delete
Hope this helps.
Thanks to this discussion, I could solve a huge permission problem on my Library user folder, just after upgrading to Lion. Thanks!
Also I'd like to add that purging ACLs on a specific folder can be done without terminal using MacPilot