Two planning books with same planning area having difference in data

Hi All,

I am having two planning books with same planning area. When I check the planning book X, I could see perfect data, but when I see another planning book Y, I could see difference in data. What will be the reason, I could see this issue for some products only. What will be the reason.

When I work with pln.book Y  with perfect combination at first , I could see correct data, then If I see the data at details(all) level, both Planning books are matching...but if I Y pln.book in detail(all) level at first , data difference is there...

Thanks,

Venu..