Posssibly... clue for me is "but after saving a view as Version 28 "Playlists" View..."
The menu item View > Load/Save View" is not the same as the Load and Save options available in the customise view dialogue.
The one in the View menu saves the current tabs, dual view layout, etc and restoring there, returns the user to that layout in one click should it ever get lost. These are saved in the registry.
The one in customise view, which is, I think, the one you're working with, may not work with playlist views. I can save a view from there, and the jvi file is saved, but I can only access it via the 'load view from file' option, and it doesn't load anything.
I think the jvi files are only available for library views, not playlist/smartlist views, which does beg the question, where is the bug...
Is the bug that those views are showing save/load options, or is it that those options do not appear to be working?