If you get a replacement Smoothwall box (or a new school is connecting) you will most likely get the new version. If so in order to make the smoothwall VPN work you will need to make the following change to the newly exported OVPN file (open in notepad):
Add the line:
tls-cipher MD5
...after the line...
under key-direction 1
import it again in to the VPN software and it should now connect.