I've noticed a small usability issue with 5.0.
When setting up a 'fixed aspect ratio' selection, I used to be able to click in the box for the X value, type it in, then tab-tab across to the Y-value. This no longer works - the tabbing sequence briefly goes to the 'flip' button (but doesn't actually stay on it), then seems to just disappear.
Otherwise though, many thanks for developing and maintaining PDN - it's such a useful tool, even though I only use a tiny subset of its capabilities.