Still no 64-bit support?
You can run Paint.NET in 32 bit mode by using a tool from Microsoft called corflags.exe
It comes with the .NET SDK
run it like this in the Paint.NET folder (command line prompt):
corflags paintdotnet.exe /32BIT+
to revert to 64 bit mode do:
corflags paintdotnet.exe /32BIT-
I figured out this after reading this blog post.
I'm not sure about the Licensing so I can't provide a package with corflags.exe.
On my system it is located in the folder "C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\bin\x64\".
It would be nice if Paint.net was provided with a 32bi