Normally, the secondary PIX will not arp for anything, unless the primary goes down and secondary will swap the IP address and MAC of the primary box, and start arping for that address.
From the logs, it looks like someone is trying to reach 126.96.36.199 on port 443 and primary pix arps for it and a connection is built up, but next thing is that it tears down the connection for some reason and Secondary PIX builts the connection for same. This could be due to Failover triggering, and perhaps you have Stateful failover so all the connections built on the primary are now going to be built on Secondary. Check to see who is the 'active' failover PIX at that time, that is where the TCP connections should be built on. Maybe your PIX is failing over to secondary.
I don't think it is this bug you are hitting. This one is primarily if you are loosing ARP entry on the PIX for an HSRP address, which i don't think is your problem. The TCP connections built on secondary are for port 443, which is SSL and nothing to do with HSRP.
As i mentioned earlier, did you check if you have stateful failover and that if the Secondary unit is/was the ACTVIE unit at the time when you see the connections being built on secondary PIX from the logs.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...