MIRO problem

Dear Expert

i have one Issue regarnding the MIRO

PO price like :- 600000

service tax amount :- 5000

then i am posting the MIRO the balance amount wich is 595000 are posted in MIRO

but at the time of Open itme the balance amount 2000 is reflected at the time of open item managemant

So please revert back me how to re-posted the balance amount

and amount how to close

Regards

MERUGU HAREESH