In some embodiments of the present invention, a data storage system includes a controller and a non-volatile memory array having a plurality of memory pages. The controller performs a method that efficiently resolves the lower page corruption problem. In one embodiment, the method selects programmed lower page(s) for which paired upper page(s) have not been programmed, reads data from those selected lower page(s), corrects the read data, and reprograms the read data into those lower page(s). Since the number of lower pages in this condition is typically low (e.g., several pages in a block with hundreds or thousands of pages), this is a much more efficient method than reprogramming the entire block. In another embodiment, a similar reprogramming method is applied as a data recovery scheme in situations in which only lower pages are programmed (e.g., SLC memory, MLC memory in SLC mode, etc.).