92 Byte ICMP Blocking Problem

We started blocking 92 Byte ICMP packets on our ingress points on our core backbone routers. This was a recommendation from Cisco to help mitigate the effects of the Nachi worm. Since then, we have been hammered with customer complaints concerning the inability to talk to mail servers and ssh to their servers, as well as other weird network issues, all centering around the time we started blocking 92 Byte ICMP packets. Has anyone else seen this, and if so, is the only resolution to stop the blockage of 92 Byte ICMP Packets..? Thanks Richard