Just tried it and it's all black too. The developer has built its own gstreamer module, and it must be somewhat broken. With previous versions I had it working, just copying the gstreamer module from the SDK package to the right place. Workaround: install the version from extras-testing (0.4.4-2), copy libgstximagesrc.so to /usr/lib/gstreamer0.10/ and don't update load-applet until this is fixed.