Looks like that the problem is in Safari. For some reason page the
following load/refresh notifications aren't being sent:
WebViewProgressStartedNotification
WebViewProgressFinishedNotification
WebViewProgressEstimateChangedNotification
I'm not sure if it's a bug or a permanent security (or for some other
reason) change.
I'm not a greasekit admin/developer too. I was trying to make it work,
but can't think out any workaround for the problem above.
As for now I'm using NinjaKit. It's really buggy and not as convenient
for user script development as GreaseKit, but I have no other choice :
(.
Pavel