To solve this problem, this this order until a resolution is found:

1. Do a git pull of cdk or all four gits and rebuild. I changed two things in the build of the gstreamer stuff: gst_plugin_subsink was never refreshed after the first pull from its git (most probably the cause of your problem) and gst_plugins_dvbmediasink first patched, and then pulled if a newer version was in its git, overwriting the patches. Both problems are inherited from the ddt-git.
2. Empty your Archive directory and do a build after a make distclean in the cdk directory. This will fetch all the latest versions from the net.
3. If still problems, try and installing libgstreamer1.0-dev, as the gstreamer version was changed from 0.10 to 1.6.1 in the build environment recently.

Regarding the 3G-modem support, I had a look. First, I lack the hardware to test. The only hardware I found in the far east comes with a closed source Windows driver only, so building the driver may have to be done from scratch. Lastly, I have a feeling this is a lot of work for a very small audience. For which device would you like support so I can have a more detailed look?

Regards,

Audioniek.