Stop wired connection from disabling wifi

I have 2 different laptops that I am using for work. Both need to connect to our corporate network over WiFi but I -also- need to connect them to an unrouted private network over ethernet (for remote management via RDP). Both are using Windows 7 Ultimate (the Lenovo is 64bit, the HP 32bit). This is working on one machine (Lenovo Thinkpad T61p) and not on the other (HP 2710p).

On the Thinkpad it just works. I assigned the wired (unrouted) connection a static IP with no gateway and then connected the wifi as normal. Perfect. I have a Gb ethernet connection for doing RDP to this machine.

On the HP 2710p, whenever the ethernet is plugged in it will disconnect the wifi until the ethernet is disconnected.

I'm assuming that this is due to something with the driver on the HP trying to be "smart" about how it roams. Does anyone know where the setting might be to disable this functionality? I realize that this probably ends up being a driver issue, but I'm hoping there is a common way to disable the function.

PS. The 2710p wifi is the Intel 4965AG and ethernet is the Intel 82566MM.

Maybe try this on the wireless NIC of the HP

Go into Network and Sharing Center
Change Adapter Settings
Properties
Power Management

Then.....make sure Allow the computer to turn off this device to save power is UNCHECKED

Turns out it was a setting in the BIOS. Got the answer here: Re: HP 2710p - Stop wired connection from disabling wifi - HP Support Forum

it's usually put in place as a security measure.
Reason's being that you could be wired to your corps secure network and you fire up an unencrypted wireless connection, this would bridge the networks, nullifying your corporates expensive hardware firewall and allowing all and sundry (wireless connected clients) un metered access to your LAN.