In the time zone change Russia took this March, Irkutsk Oblast began using Krasnoyarsk Time while Buryatia didn't, so a split of Asia/Irkutsk is in order, creating Asia/UlanUde (?).

Additionally, the elves at Wikipedia have discovered that Tomsk Oblast didn't change to Omsk Time at the same time as Novosibirsk Oblast.
http://en.wikipedia.org/wiki/Time_in_Russia#Tz_database
Source (in Russian)
http://newsru.com/russia/01may2002/clock.html