Formats are misbehaving

I'm trying to change the block size on my document. You can see that the first left page is short, compared to the second left page. 


The first left page uses style A_pg2, and we've checked to be sure this is the style being called in. Previously it had a copyright box below the text, which I removed. I lengthened the Main boxes from 50p to 56p. I also tried making the length shorter, and they won't change at all. 





Any ideas why this is happening? Thank you!