SBRgain on revaluation of the previously held interest..BIG problem

Please help me! For what I know, the gain on revaluation of the previously held interest is taken to profit or loss for the year, hence to retained earnings. (for FV through P/L) June 2013 (Equity investment to Sub) 2012 14% 280m 2013 14% 310m ? Why the gain of 30m in Trailer's books on Trailer's investment in Caller need to be reversed from Retained earnings on consolidation? ? June 2012 ( equity investment to SUb) Robby buy 80%, treat investment at fair value through OCI cost of investment 50m Financial statement of individual = 55m ? why the revaluation gain of 5m which needs to be reversed out from other component of equity? ? June 2014 Merchant own 60% , and then dispose 8% .. showns gain and loss in other comprehensive income in 2013, carrying vale of investment =90m in 2014, before the disposal carrying value= 95m ?why the gain on revaluation of investment is eliminated? ?