Crashes after selecting an image - Parameter is not valid

[Grum]

This is the second time this has happened to me in a month... Multiwall is working fine for many days, allowing me to select new wallpapers whenever I want to. Then one day, I try to select a new wallpaper from the gallery and get a nasty messagebox saying...
Parameter is not valid.
at System.Drawing.Bitmap..ctor(Int32 width, Int32 height, PixelFormat format)
at Sumo.Framework.ImageHeIperStretchImage(Image image, Int32 width, Int32
height)
at -.<strange graphic character here> ()
at -. ()
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext,
ContextCaIIback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext,
ContextCaIIback callback, Object state)
at System.Threading.ThreadHeIper.ThreadStart()

Once this happens, I am then unable to restart Multiwall - even after rebooting the PC. It subsequently comes up with the same error message as soon as it opens. The only thing left to do is uninstall it and start all over again.
I am using the 64-bit version 1.0.26 installer (though it has installed itself in the x86 Program Files folder and program properties show it to be v1.0.0 )

Help...

[sumo]

Damn!!

I will look into it!