I use phproject and I can recommend that.
http://www.phproject.org/I think there is a contrib with a not upgraded version.
You can download it from the homepage as well, but you will then have some problem with the document upload function.
The problem with the sme server is that it has a php security function that on the one side improves security, on the other side reduce flexibility for running different kind of application.
It possible to dissable this securityfunction or you will have the Phproject running with all functions except for the dokument upload.
By the way .. The SME 5.6 behaves a little bit different from the 6.0.1 .. If you install phproject as a subdirectory under the Primary ibay at a SME 5.6, all functions on the phproject will work without modifications, also the document upload.
I think Phproject is a very usable and dependable application.