Se'ir's fifth son was called Dishon and his seventh son, Dishan (36:21, 30). When the Torah lists their sons (36:26,28), both of them are called Dishan!
Ramban: The Torah is not particular about interchanging their names, unless they occur in the same Pasuk (e.g. 36:21). However, here the Pasuk must call Dishon (ben Se'ir) Dishan, lest we think that it is his nephew Dishon ben Anah, who was mentioned in the previous Pasuk.
Kol Eliyahu: Really, both of them were named Dishon, like we find in Divrei ha'Yamim I 1:41-42. However, when the Trup (cantillation) is Esnachta or Sof Pasuk, this changes it to Dishan. 1 However, Dishon ben Anah is always called Dishon even when the Trup is Esnachta, e.g. Divrei ha'Yamim I 1:41.
These Trup notes often change the vowel to Kamatz, e.g. the word Mayim (Bereishis 1:6); (or Kesef /Kasef (Shemos 38:17)).
Bnei Etzer were Bilhan, Za'avan and Akan; these names allude to panic, dread and affliction (like in Yechezkel 28:19; Devarim 28:25; Tehilim 66:11 - Sechel Tov). What is the significance of this?
Ohr ha'Chayim: In order to prepare an Otzar (storehouse) in the world to come), Hashem gives afflictions in this world. One who wants such a storehouse should despise this world and accept afflictions.
