I downloaded the most recent Gridcoin snapshot at http://download.gridcoin.us/download/downloadstake/signed/snapshot.zip and copied the files to my Gridcoin configuration directory (/Users/Common/Library/Application Support/GridcoinResearch on my Mac) only to find that my wallet started rebuilding from scratch. This didn't happen with the previous snapshot I used. A file or directory must be corrupt. blk0001.dat grew without adding any truly new blocks. I've decided with the Forkapalooza going on to just to just build from scratch and wait a few days. It's not like I have some spending to do.