For about a month, we are having problems connecting to our VPN using a Vodafone 3G USB modem device. Previously we had no problems for about 9 months when we have been using it.

The same device connects fine if forced to use GPRS, but won't authenticate over 3G with the following error, where it should continue and create the ESP-SA.

IKEQMTimeoutHandler: Packet retransmit exceeded the limit! the SA will be deleted.

Anyone had similar problems, or any ideas on what could be causing this.

Vodafone say they have changed nothing - nothing new there - and also that their GPRS and 3G networks use the same routers and do not stop any packets, so not a lot of help.