Dear Taro!
This was due to a silly mistake. IHC account balancing date was set to last date of month and wasn't changed after that. IHC calculated interest amount according to account balcning date, but did not post to GL untill account balancing date was changed again.
I observed system response that IHC balancing date and IHC posting date need to be changed so that interest amount is posted to correct GL accounts.
Regards
Ashok kumar