Yesterday I had an option of putting two 4x6 pictures on a page. That option is gone and I can only put four 4x6 pictures on a page. How do I change the settings?

I am using Adobe Acrobat 9 Standard.  Yesterday I was able to put two 4x6 pictures on a page.  Today I can only put four 4x6 pictures on a page.  How do I change the settings?  And why all of a sudden do things change without any input from me?

Sharon Merkle