This is not actually a bug, just a minor issue I encountered by chance:
When you List keyboard shortcuts to print, in Pattern Editor > Navigation section, F9 through F12 keys are described as Jump to rows 0, 16, 32 & 48. This is only true if the pattern is 64 rows long. These keys actually jump to the beginning, 1/4, 2/4 and 3/4 of the whole pattern length respectively.
edit: the same description (as expected) is found in preferences menu > keys.
Sorry if it has been mentioned before.