VPN usage after upgrading PIX 506E

Before to upgrade Firewall version and PDM I was using VPN perfectly. Once upgraded I can connect with VPN.

Show ver before upgrade:

Cisco PIX Firewall Version 6.1(2) Cisco PIX Device Manager Version 1.1(2) Compiled on Fri 16-Nov-01 14:28 by morlee Hardware: PIX-506E, 32 MB RAM, CPU Pentium II 299 MHz Flash E28F640J3 @ 0x300, 8MB BIOS Flash AM29F400B @ 0xfffd8000, 32KB

0: ethernet0: address is 0009.b718.b578, irq 10 1: ethernet1: address is 0009.b718.b579, irq 11 Licensed Features: Failover: Disabled VPN-DES: Enabled VPN-3DES: Disabled Maximum Interfaces: 2 Cut-through Proxy: Enabled Guards: Enabled Websense: Enabled Inside Hosts: Unlimited Throughput: Unlimited ISAKMP peers: Unlimited

Show ver after upgrade:

Cisco PIX Firewall Version 6.3(4) Cisco PIX Device Manager Version 3.0(2) Compiled on Fri 02-Jul-04 00:07 by morlee pixfirewall up 1 day 23 hours Hardware: PIX-506E, 32 MB RAM, CPU Pentium II 300 MHz Flash E28F640J3 @ 0x300, 8MB BIOS Flash AM29F400B @ 0xfffd8000, 32KB

0: ethernet0: address is 0009.b718.b578, irq 10 1: ethernet1: address is 0009.b718.b579, irq 11 Licensed Features: Failover: Disabled VPN-DES: Enabled VPN-3DES-AES: Disabled Maximum Physical Interfaces: 2 Maximum Interfaces: 2 Cut-through Proxy: Enabled Guards: Enabled URL-filtering: Enabled Inside Hosts: Unlimited Throughput: Unlimited IKE peers: Unlimited

After upgrade I don't have change configuration.

How can I resolve it?

THANKS!