[ubuntu] Help configuring network with differente Host IPs in Virtualbox 4.3.1

I have read many reviews on intenet but I could not solve the problem that I describe bellow. I need some help please


I have a notebook with ubuntu 12.04 virtual box running as a guest in a Windows 7 64bits host.

I use bridge connection under virtual box.

Everything was ok at home, that is, both guest and host sees each other and guest could connect to internet.
My guest has a static IP and my host dhcp.

But when I moved to work where I have different gateway and had to put a static ip to my host, it wont access the guest anymore and guest has no internet connection.

---------------------------------------------------------------
Host at home:

DNS: 192.168.1.1
Subnet: 255.255.255.0
Ip: 192.168.1.xxxx (get dinamycally)

Guest:
Set as static ip.
The /etc/network/interfaces file:

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 192.168.1.25
netmask: 255.255.255.0
gateway 192.168.1.1
dns-nameservers 8.8.8.8 192.168.1.1

----------------------------------------------------------------

Host at work:
Ip: 192.168.0.125
Subnet: 255.255.255.0
Default gateway: 192.168.0.1
Preferred DNS: 192.168.0.1

Guest:
Set as static IP

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 192.168.1.25
netmask: 255.255.255.0
gateway 192.168.1.1
dns-nameservers 8.8.8.8 192.168.1.1
-----------------------------------------------------------------

How to solve this so I can use virtual box both at home and at work ?? What is the correct way of doing this ?

Thank you all in advanced !!