VPN--can connect wirelessly but not via ethernet

So I have a Mac Pro and a MacBook Pro, both running the most current version of SL.

I use VPN to connect to my work site. My Mac Pro is connected to my Airport Extreme router via an Ethernet cable. My laptop connects wirelessly. Randomly (and this has occurred in the past), I cant connect when using my desktop. If I try my Cisco VPN program, it just repeatedly says "not connected" at the bottom of the screen, or sometimes "(backup)". The log is as follows:

1 22:05:26.998 12/17/2009 Sev=Info/4 CM/0x43100002
Begin connection process

2 22:05:26.998 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -28 sending packet. Dst Addr: 0xC0A801FF, Src Addr: 0xC0A80164 (DRVIFACE:1158).

3 22:05:26.998 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -28 sending packet. Dst Addr: 0xC0A80DFF, Src Addr: 0xC0A80D01 (DRVIFACE:1158).

4 22:05:26.998 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -28 sending packet. Dst Addr: 0xC0A8A2FF, Src Addr: 0xC0A8A201 (DRVIFACE:1158).

5 22:05:26.999 12/17/2009 Sev=Info/4 CM/0x43100004
Establish secure connection using Ethernet

6 22:05:26.999 12/17/2009 Sev=Info/4 CM/0x43100024
Attempt connection with server "pvc.partners.org"

7 22:05:27.000 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -16 sending packet. Dst Addr: 0xAADFA8BE, Src Addr: 0x00000000 (DRVIFACE:2384).

8 22:05:27.000 12/17/2009 Sev=Info/4 CM/0x4310002E
Unable to reset TCP connection

9 22:05:27.000 12/17/2009 Sev=Info/4 CVPND/0x43400019
Privilege Separation: binding to port: (500).

10 22:05:27.000 12/17/2009 Sev=Info/4 CVPND/0x43400019
Privilege Separation: binding to port: (4500).

11 22:05:27.000 12/17/2009 Sev=Info/6 IKE/0x4300003B
Attempting to establish a connection with 170.223.168.190.

12 22:05:27.000 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -16 sending packet. Dst Addr: 0xAADFA8BE, Src Addr: 0x00000000 (DRVIFACE:1281).

13 22:05:27.100 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -16 sending packet. Dst Addr: 0xAADFA8BE, Src Addr: 0x00000000 (DRVIFACE:1281).

14 22:05:27.200 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -16 sending packet. Dst Addr: 0xAADFA8BE, Src Addr: 0x00000000 (DRVIFACE:1281).

15 22:05:27.301 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -16 sending packet. Dst Addr: 0xAADFA8BE, Src Addr: 0x00000000 (DRVIFACE:1281).

16 22:05:27.401 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -16 sending packet. Dst Addr: 0xAADFA8BE, Src Addr: 0x00000000 (DRVIFACE:1281).

17 22:05:27.501 12/17/2009 Sev=Warning/2 CVPND/0x83400011
Error -16 sending packet. Dst Addr: 0xAADFA8BE, Src Addr: 0x00000000 (DRVIFACE:1281).

18 22:05:27.501 12/17/2009 Sev=Info/4 IKE/0x43000075
Unable to acquire local IP address after 5 attempts (over 5 seconds), probably due to network socket failure.

19 22:05:27.501 12/17/2009 Sev=Warning/2 IKE/0xC300009A
Failed to set up connection data

20 22:05:27.501 12/17/2009 Sev=Info/4 CM/0x4310001C
Unable to contact server "pvc.partners.org"

21 22:05:27.501 12/17/2009 Sev=Info/5 CM/0x43100025
Initializing CVPNDrv

22 22:05:27.501 12/17/2009 Sev=Info/4 CVPND/0x4340001F
Privilege Separation: restoring MTU on primary interface.

23 22:05:27.501 12/17/2009 Sev=Info/4 IKE/0x43000001
IKE received signal to terminate VPN connection

24 22:05:27.502 12/17/2009 Sev=Info/4 IPSEC/0x43700008
IPSec driver successfully started

25 22:05:27.502 12/17/2009 Sev=Info/4 IPSEC/0x43700014
Deleted all keys

26 22:05:27.502 12/17/2009 Sev=Info/4 IPSEC/0x43700014
Deleted all keys

27 22:05:27.502 12/17/2009 Sev=Info/4 IPSEC/0x43700014
Deleted all keys

28 22:05:27.502 12/17/2009 Sev=Info/4 IPSEC/0x43700014
Deleted all keys

29 22:05:27.502 12/17/2009 Sev=Info/4 IPSEC/0x4370000A
IPSec driver successfully stopped



The weird thing is, I can connect when using my laptop, wirelessly, without any problems. I have the same issue when using the built-in VPN from Apple.

I have ports forwarded to my desktop but not my laptop (62515,4500,500,5500,1701,10000); but even if I turn off VPN port forwarding, nothing changes.

Any ideas?