MM period

Hi All,

We closed the MM period 12, 2009 and opened period 01, 2010. After that user come to know that he want to do 3 entry. so he remove the tick mark from "Disallow Backposting generally". After that done 3 entry for MIRO in 12 2009 period. But after that he again tick and select this option. But after this system is saying Postion is not allow in 12 period 2009 at time of MIGO. But system is allowing entry in MIRO.

Is there any solution to stop this?

Regards,

Zubin