Back to XP :(

I am, as we speak, demoting my work machine from Vista to XP. I am not doing this because I hate Vista, nor have there been any real problems with it - in fact I love Vista. I am doing this under duress. A client of ours uses some Cisco VPN software, that works fine on Vista. However, their management has decided that they do not wish to allow ANY Vista machine to access their network and as such block it with a firewall rule managed by the Cisco kit. As such I cannot connect and do my work. We tried to get them to accept that Vista is here now - but no joy. XP here I come again... I am disappointed.