This update available at Paint.NET or use the integrated update tool. From the site:

2.61 Released: March 30th, 2006
This small update fixes a few uncommon bugs, and adds a "Donate" item to the Help menu that links to our donation page.

Fixed crash when clicking File->New when there is a malformed image in the clipboard
Fixed several crashes related to pressing Ctrl+Z (Undo) or Ctrl+Y (Redo) before releasing the mouse button while still drawing
Fixed Zoom Tool "haze" remaining after pressing Ctrl+Z before releasing the mouse button
Fixed uninstaller not removing Start->Programs menu shortcut
Fixed "Auto" button in Adjustments->Levels not updating one of its sliders
Fixed a few small plugin API problems
Fixed a race condition in the file loading code related to EXIF tags
Added "Donate" to Help menu