How to make "Page specific visibility settings" for blocks more flexible? My problem is that depending on a running mode my Drupal website might have either regular permalinks, or pretty, aliased ones. And "Page specific visibility settings" for blocks on specific pages (Show on only the listed pages) do not work across the modes.

It would be logical if let's say: node/23 syntax could work in any case, but it seems that it doesn't.

Do I have to change every setting for every block every time I switch permalink structure? Or there is more flexible solution to this?
If you need to control block visibility then the Context module is the way to it.

(edit) If you use the Context module you won't have to mess around with these types of things and more importantly neither does Drupal which in fact makes it faster. You can read more about Blocks, Context and Panels, another alternative to Blocks, here.