[vpn-help] Windows negotiation timout, works in VM on same PC though

[shrew.10.k3npiduse3ku at spamgourmet.com]

Hello,
I'm running Shrew on Windows 2003 with the VPN server running on a
FritzBox 7230. Problem is that I always get the error "negotiation timout
occurred" when trying to connect. However with the same configuration I'm
able to connect just fine from a Win XP VM running on the same PC.

The non-working one has this in ike.log
11/09/24 13:50:41 ii : local is CISCO UNITY compatible
11/09/24 13:50:41 >= : cookies 4a378bc29dcb0f2c:0000000000000000
11/09/24 13:50:41 >= : message 00000000
11/09/24 13:50:41 -> : send IKE packet 192.168.2.101:500 -> 1.2.3.4:500 (
526 bytes )
11/09/24 13:50:41 DB : phase1 resend event scheduled ( ref count = 2 )
11/09/24 13:50:46 -> : resend 1 phase1 packet(s) 192.168.2.101:500 ->
1.2.3.4:500
11/09/24 13:50:51 -> : resend 1 phase1 packet(s) 192.168.2.101:500 ->
1.2.3.4:500
11/09/24 13:50:56 -> : resend 1 phase1 packet(s) 192.168.2.101:500 ->
1.2.3.4:500
11/09/24 13:51:01 ii : resend limit exceeded for phase1 exchange

while in the working one it goes
11/09/24 13:46:54 ii : local is CISCO UNITY compatible
11/09/24 13:46:54 >= : cookies 1ab2fa2a15e12b5d:0000000000000000
11/09/24 13:46:54 >= : message 00000000
11/09/24 13:46:54 -> : send IKE packet 192.168.10.129:500 -> 1.2.3.4:500 (
526 bytes )
11/09/24 13:46:54 DB : phase1 resend event scheduled ( ref count = 2 )
11/09/24 13:46:55 <- : recv IKE packet 1.2.3.4:500 -> 192.168.10.129:500 (
464 bytes )
11/09/24 13:46:55 DB : phase1 found
11/09/24 13:46:55 ii : processing phase1 packet ( 464 bytes )
11/09/24 13:46:55 =< : cookies 1ab2fa2a15e12b5d:773f72c193648d3d
...

I can provide the dump-ike-decrypt.cap file on request if it's required to
identify the issue.
Any help would be appreciated.

Lars