[vpn-help] Random disconnects.

[impactpl]

Hello,

i'm having weird problem with Shrew VPN Client.

Connection is being established without any problem, but

after random amount of time (sometime 30 minutes, other time around 1 
hour) i'm disconnected.

This happens everytime.

The same problem is with both 2.1.6-* and 2.1.5 versions.

Settings:

Client:

NAT Traversal: enable
NAT Traversal Port: 4500
Keep-alive packet rate: 15 secs
IKE Fragmentation: enable
Maximum packet size: 540 Bytes

Other options:

Enable Dead Peer Detection: YES
Enable ISAKMP Failure Notifications: YES
Enable Client Login Banner: YES

Phase1:

Exchange Type: aggressive
DH Exchange: group2
Cipher Algorithm: 3des
Hash Algorithm: SHA1
Key Life Time limit: 86400
Key Life Data limit: 0

Enable Check Point Compatible Vendor ID: YES

Phase2:

Transfor Algorithm: esp-3des
HMAC Algorithm: SHA1
PFS Exchange: group2
Compress Algorithm: disabled
Key Life Time limit: 28800 sec
Key Life Data limit: 0

My operating system is: Vista x64 and Windows 7 32bit (same problem)
Hardware: Cisco ASA 5510.
I'm using wireless connection.

When i use Cisco VPN client connection is being established for more 
than 3 hours without any problem.

Maybe someone had the same problem and know solution?

Greetings,
Mike