I created a manual journal for an AP invoice (Journal source manual and categories invoice)transaction Dec 13, anytime i run a revaluation it calculates gains and losses of the journal even though I have closed the dec 13th period.
Please Gurus help about this.Secondly I will like to know how revaluation handles manual journals not subledger journals

Revaluation is not based on any particular journals, subledgers or manual. It is simply based on balances.
Oracle keeps track of balances entered in foreign currency and entered in local currency separately.
Also Oracle keeps track of how much foreign currency balances are revalued already (beq columns of gl_balances tables). This is how revaluation works. It will not discriminite based on where the journals came from. Also your argument that the dec-13 period is closed, therefore those journals should not be picked up for revalution is not valid. As explained, revalution is based on balances. It reads YTD balances for balances sheet accounts and you can control which balances should be read for income statement accounts (PTD/YTD) through profile options. Hope that helps.

Thanks very much for the response, really appreciated,I will give you an example of a journal which has been revalued contineously,secondly what is the profile option name.Thanks a lot

Profile Option:
GL: Income Statement Accounts Revaluation Rule