Not sure about your specific problem but just wanted to give you a heads up that TamTam does not seem to have been developed since May 2010 (that's version 1.30 which is the latest as far as I can tell. Which version are you using?)
I am extremely skeptical that it can interact with SVN 1.7 since the way the local copy is stored has changed.
In a way we are in the same boat, we have been using PushOK until now relatively successfully however it too does not support SVN 1.7 (they released an RC but it is not working for us). For now what we are doing is running 1.6.16 client on our machines, it connects ok to the SVN Server (which is 1.7).
However we are on the lookout for plugins supporting 1.7 and that's how I have reached this thread (no luck so far).