We’ve received feedback from some customers about instability with the VPN feature in the SA520. We released a firmware upgrade in March 2011 that resolves that issue. You can find the software here: http://www.cisco.com/cisco/software/release.html?mdfid=282414018&flowid=4827&softwareid=282364316&os=Windows&release=5.0.07.0440&relind=AVAILABLE&rellifecycle=&reltype=latest.
The link mentioned on this posting is for Cisco VPN client and not for SA520. So I am not sure if the issue reported by customers is related to Cisco VPN client or SA500?
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