Autocrop in batch mode only applies to first couple of pages

Hi all,

I use this awesome app for scanning books. 

Let's say I have scanned 100 pages in batch mode. I want autocrop to apply to all pages before I save as pdf. However, it only seems to apply to the first page! When I manually press the crop botton and then press autocrop, however, it properly finds the boundaries. Could it be a bug or an issue that happens for large number of images?

Thanks