If you're a Barry user please give the new version a try and file bugs for any problems you run into. I'm not sure the udev rules are correct and have no idea how the tethering/pppd stuff works. The pppd files are just installed into /usr/share/doc for now since I'm not 100% sure where the proper place for them is. There is also a new plugin for opensync that could use some testing.
For more info on using Barry there is some good documentation at http://www.netdirect.ca/software/packag