D3DFMT_UNKNOWN is not a valid format

Hey guys,

I just made a fresh install of windows this week, and I'm getting some errors in Torque (errors I've never had before). No hardware has changed - it was just a format/install. It happens when using the DX debug runtime with FSAA enabled (although i'm pretty sure it happens in Retail too - one just doesn't get the error).

The error:

--------------
Attempting to set resolution to "800 600 false 32 60 4"
Accepted Mode: 
--Resolution : 800 600
--Full Screen : No
--Bits Per Pixel : 32
--Refresh Rate : 60
--FSAA Level 4
--------------
Direct3D9: (ERROR) :D3DFMT_UNKNOWN is not a valid format. CheckDeviceMultiSampleType fails.

Where it happens (stack trace):

GFXPCD3D9Device::validateMultisampleParams(_D3DFORMAT format=D3DFMT_UNKNOWN)
GFXPCD3D9Device::reset(_D3DPRESENT_PARAMETERS_ & d3dpp={...})
GFXPCD3D9WindowTarget::resetMode()
Win32Window::setMode(const GFXVideoMode & mode={...}) 
etc...

My setup:
TGEA 1.7.1
Windows XP SP3
NVIDIA GeForce 8800 GTS 640MB
Driver 178.24
DirectX Runtime 9.0c
DirectX SDK March 2008

Any ideas?
Lorne