I am noticing a problem with a UC520 dropping IPSec tunnels. They are now on the most current EA software pack with the same issue. This issue is very similar to the following bug I have had in the past:
CSCsv43385DMVPN Hub may loose connectivity w/ spokes due to wrong cef adj encap
The workaround for this one was to take take of the tunnel mode and re-add, or delete and recreate the tunnel interface. Although this was for a DMVPN (tunnel mode gre multipoint). The one I am having an issue with now is just an ipsec tunnel (tunnel mode ipsec ipv4). however the symptoms are the same. the tunnel drops after a day or two, and doens't come back up untill i shut/no shut it.
Any ideas? is there another bug out there? This is in 7.1.3EA as i said, which is 12.4.22YB4 I think?