In that case, if it works with SEF completely disabled, but doesn't work with SEF enabled either with or without JoomSEF, the module doesn't support SEF URLs. You should probably contact the module's author to implement better SEF support.
Or if you're interesting, we can check the module's source code and make required modifications for you as a paid service. The price would depend on the time we'd need to do that:
www.artio.net/e-shop/support-services (usually we require purchasing 1 hour to check what exactly is the problem and estimating the time needed to fix it)