Create a long line of text (300 chars or more) and add a carriage return to the end. Select all and copy, then restart Notepad++.

In the new file, paste the text you just copied. The text pastes in okay, but the horizontal scrollbar doesn't resize itself accordingly. If you scroll it to the far right, you don't actually get to see the end of the line you pasted. Clicking on the line and using the cursor keys reveals more text, hitting 'end' will move you to the end of the line and properly resize the horizontal scroll bar. Once you've done this once, all subsequent windows will have the same sized horizontal scroll bar until you restart the program.

Quite annoying if you're copy/pasting XML into Notepad++ from somewhere else, which is how I noticed it. :-)

Great work on the editor, btw - thanks!