This morning I used PrintKey 2000 to capture my screen, copied to the clipboard, opened Paint.Net pasted the image. Cropped to 1024 x 768 and saved as Jpeg and receive, Unknown File Size and if I continue it fails. There are two significant points to note:
1.) I can save in any other format just fine.
2.) It's not consistent. Sometimes it works... sometimes it fails.
I was using the latest release. Thinking something was corrupt, I forced an update to the new 3.5.3.3755.37963 Beta and I am having the same error. Guessing it has something to do with one of the various add on zips that I installed months ago. Has anyone else experienced this?