Production order release problem

Hello PP Gurus,

We are facing problem during production order release,System is creating a log as- Release operation" is not allowed (ACT 3099993 1200 ) here 3099993 is order and 1200 is operation number.

We have checked in operation overview in production order,There are three operations and first two operations are not having any system status but third operation is having CRTD status.

There are many production orders for same material but only few of them is having this problem.

When i did read pp master data then all operation gets CRTD status and system is allowing me to release the order.

But this is temporary solution,I am finding the root cause but in vain!

Can sombody put light on this?

Thanks