I have a similar issue. Windows7 Pro, Paint.Net.4.0.5.
Had been seeing this a few times but was unclear what steps I did to create it. In this case I can repeat it, although I am using my same paste buffer.
I used snipping tool to create a paste buffer of an image, I do this all the time, most of the time it works. In this case I pasted the buffer into an existing instance of Paint.Net and it took it just fine. While the drag selection box, left over from the paste, is still active I go to Image->Resize->
x [by absolute Size]
x [Maintain Aspect Ratio]
The canvas is 800x600 and that's the initial display
The paste image is about 160x120, the canvas is 800x600.
Pixel size and print size are in pixels/cm, Bicubic has an asterisk.
Resampling is "Best Quality".
I type in 32 in the Width and it puts 24 (the correct ratio) in Height and click OK.
Paint.Net crashes, no report.
In %AppData%->Paint.Net->Session I have a numeric directory and several 5 (I did this 5 times to confirm) ... I'm guessing "reports" in there. They have some textual intermixed with binary data but I did not find a crash report that was readable to forward.