NAS and Proxy

[ags131]

Hello, I'm trying to work on improving my parent's Pi running xbian, they are on satellite internet so suffer from high ping, and when they go over their 10gb monthly limit (Easy with Steam...) it slows to sub-dsl speeds. This is VERY noticable when updating the library in XBMC. I've setup a netbook that will be running the OpenMediaVault NAS distro and moving the external HDD off the Pi, I realize this shouldn't affect performance on the Pi as its still bottlenecked by usb, but this will allow faster access via the network.

The Pi is currently conected via WiFi, now, my idea is to connect the pi to the netbook via ethernet, then connect the netbook to the network via wifi.

Now for the main question: Since the Pi will be going through the netbook for network access now, (Via a bridge between wifi and lan), is there a way to cache tvdb calls to speed up library updates? Many shows in our collection are no longer airing so dont need updated info.
I have also tried generating nfo files but xbmc still tries scanning TVDB.
The netbook is running debian so I can easily install software.

It took several hours the other day to scan after updating to beta 1.1, this would me much quicker if I can cache the calls more locally
(I did a full reinstall to beta 1 then did the update to 1.1)