Unstable IPSEC VPN connection

Archived from groups: comp.dcom.vpn (More info?)

Hi,
I'm setting up a VPN connection for my company, we are using a fortinet
firewall/vpn server.
To connect to the fortinet we use a vpn client made for this firewall.
I can establish the ipsec connection, however I can't copy files larger than
400 kb, because every +- 10 seconds there is an IKE NEGOTIATION. After this
windows times out the coppy action.

I've been trying some things. When I first start the IPSEC service from
windows XP and then establish the VPN connection it keeps alive.
The only problem is that I can't access the remote network anymore.

I'm a little bit confused?

Any ideas?