Grainy photos after wordpress/buddypress upgrade?

I had two strange issues after upgrading to the most recent version of WordPress/BuddyPress? Some users just lost their photos and others now complain (and I can verify the difference) that their photos now look grainy. I am guessing the photos that disappeared were too big and maybe that setting was lowered with the upgrade?? But no idea about why some photos look grainy now that didn't before. Any thoughts or anyone else see this? Thanks! David