AkelPad

-1. install 4.0.7
0. turn wordwrap on.
1. create 10MB text file in akelpad 4.0.7
2. install 4.0.9
3. load 10MB text file into 4.0.9
4. scroll up & down
note 100% CPU.

I've gone back to 4.0.7 for now

BTW the text file consists of
"0123456789" repeated until 10MB.

Turn off hyperlinks detection. Because your file doesn't have url delimiters such as spaces, tabs and other, your file scanned to the first char.

Added:
Test version. URL now limited with 512 characters (as RichEdit).

cool