Test if this package fixes the issue, it is in , but no need to use that repo, it is safe to install with:
sudo pacman -U http://kaosx.us/repo/build/networkmanager-vpnc-0.9.10.0-3-x86_64.pkg.tar.xz
demm I tried what you suggested, but the problem still persists. The only difference is that everytime I issue sudo pacman -Syu gives me "networkmanager-vpnc: local (0.9.10.0-3) is newer than main (0.9.10.0-2)" which is normal because like you said, that package is in the dev repository and not in the main repository.
I don't understand why every time I have to enter my password, the "save password" option is disabled. That happens exactly to both the WiFi password and online accounts.