ENDIAN Firewall - PCI Compliance Scan

I'm working on getting my company to pass PCI compliance and have the following error when scanning my endian firewall (version 2.3.0).
Synopsis :

TCP reset using approximate sequence number

Description :
A remote attacker could cause a denial of service on
systems which rely upon persistent TCP connections.To correct this problem on Cisco devices, apply one of the
fixes referenced in the Cisco security advisories for

I don't really know how I should go about fixing this on they firewall. I'm running several destination NAT rules to route from RED interface to out phone switch system for the digital lines.
Hope someone can offer some advise.