Hi Strox, what you have to do is simple.
-Go in the %appdata% (in your start menu)
-Just delete the .technic file
-Go in your launcher
-Select the little option under the tekkit lite modpack
-Take "manually select a build" and in the little box, select 0.5.9
-Connect with your account, the download will start. You will be able to connect to the server.