This problem is due to the presence of Cisco bug ID CSCei73829.
This happens when a Cisco VPN Client 4.6.x connected to a Cisco IOS router configured as the VPN server passes traffic correctly. However, after the Phase 2 Security Association (SA) rekeys, repeated Phase 2 SA rekeying occurs. Also, the Cisco VPN Client disconnects.
As a workaround, downgrade the router to Cisco IOS Software Release 12.4(3).
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VPN - hardware & software clients
Sev=Warning/2 IKE/0xE3000099 Immature Navigation Termination due to error (Navigator:195)
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Cisco IOS Software Version
VPN Tunnel End Points