I think you've eliminated the remote and local filesystems and said you have no problem backing up via smb or backing up local files.
I find it interesting that the client file path is being cut off ~= 100 characters.
echo /fhome/fmike/fwerk/fsystem/fTransformer/fandroid-sdk-linux/fadd-ons/faddon-google_tv_addon-google_inc_-12/fi | sed -e 's/\/f/\//g' | wc
1 1 100
Some old versions of gnu tar had 100-character filename limits. How old is the version of tar on the problematic client?