Bug - Crash on launch if last used video mode no longer valid

[Sayonara]

Description: when launching the game, if the previously selected video mode cannot be set, the game crashes with an 'OGRE EXCEPTION' error message and no indication to the user of how to fix the problem.
Workaround: Edit ogre.cfg manually to change the selected mode
Severity: relatively minor, but the workaround might not be obvious to non-technical users
To Reproduce:
1) select a video mode, exit game, then reconfigure system so that mode is no longer valid and launch the game. (This could be done for example with the 'custom resolutions' tool in NVidia Control Panel)
2) (to simulate) manually edit ogre.cfg and enter a video mode that your system does not support

I've previously had VD working but not played it much, and just came back to it. However, when trying to launch I got the following error (from OgreLogfile):

15:39:38: D3D9 : Subsystem Initialising
15:39:38: Registering ResourceManager for type Texture
15:39:38: Registering ResourceManager for type GpuProgram
15:39:38: OGRE EXCEPTION(7:InternalErrorException): Can't find requested video mode. in D3D9RenderSystem::initialise at ..\..\..\..\..\RenderSystems\Direct3D9\src\OgreD3D9RenderSystem.cpp (line 679)
15:39:38: Unregistering ResourceManager for type Font
15:39:38: *-*-* OGRE Shutdown

There was also a dialog box that popped up with much the same message.

What seems to be happening is that it's trying to set the video mode to the one I'd previously selected; however, because I reconfigured my system since the last time I played, this mode is no longer valid and the attempt fails.

I was able to work around this by manually editing the ogre.cfg file to a valid mode, but it would be nice to have cleaner handling if this situation occurs. A number of cases could trigger it -- upgrading GPU/monitor, or the one that applies to me -- using NVidia Surround with 'bezel correction' enabled, then later disabling it which causes the corrected resolution to no longer exist.