Just try what is suggested in those threads, for example:
sudo apt-get install gnome-vfs-obexftp
Note that Ubuntu, just like most Linux distributions, has a very good software package management system. You can install and also completely remove software packages very easily. For example, if you installed gnome-vfs-obexftp with the command above and you want to remove it again, just do:
sudo apt-get remove gnome-vfs-obexftp
Don't be afraid to tinker with your Ubuntu system, you'll need to do that from time to time.