Nortel Contivity Fake/Malformed UDP Packet, Fragmented IP

Hi:

I just installed the COMODO Firewall, and am having an issue with my Nortel Contivity Software.
I can initiate a session with the Contivity, ie set up the IPSEC tunnel, but once I attempt to pass traffic over it by opening up an application on my PC, I get two errors in the firewall log.
The first indicates Fragmented IP packets.
The second indicates Fake or Malformed UDP packets.

I can make the connection work by turning off the protocol analysis and Block fragmented IP datagrams, but would like to not have to do this.

Is there a way to do this for specific IP address pairs?

thanks in advance

mderick