Sorry for pulling that out after three month of inactivity in that thread, but I think it may be interesting to see if Samsung phones in the future got this too.
I can confirm the problem on the Note 2, Android 4.1.2. Same issues like reported above.
I do have another fact to it, why this happens.If you insert a SD Card the system uses the card for saving and backing up like it normally uses the phone.The issue takes places every time the card and cache are almost full o like every time the phone says that it's full (without SD Card) and you may have a little bit of lack in handling until you delete something, the same problem it has with a card insert, but somehow it doesn't report it to you but it creates a problem.
I don't think ta it depends on how fast it reads and writes to the card, because is the card empty or half packed with things it doesn't matter to the phone at all.If you reboot without clearing the cache the phone status can't change because the problem is still there.
When I restart with cleaning the cache I got status normal with the card insert, but when the cache get a higher level it changes to modified.But I could be complete wrong.
Would be nice to know how the S4 does.