David Mikeladze did another interesting discovery: Sudan 20 piastres and 50 piastres exist also in magnetic version (probably steel core) for year 2006. You can find details in Numista (en.numista.com), where new KM numbers (KM124a & KM123a) are suggested.
20 piastres (KM124 and KM124a):
50 piastres (KM123 and KM123a):
The magnetic types bear a curved "6" in the year and also have different edge reeding:
(news by David Mikeladze)
(images taken from en.numista.com)