So my wife and I use iPhoto pretty extensively to keep our ever growing photo library managed. I've started to run into a weird issue recently with browsing through events with large numbers of photos, and I'm wondering if it's because of the size of the iPhoto library (currently around 190GB), number of photos in the events (700+) or something else entirely. The basic issue is that the thumbnail image does not refresh when scrolling, it will remain as another image in the event, and all of the thumbnails will eventually turn into the same 4-10 thumbnails (based on scaling). When you navigate to view a single image or to edit, it goes to the correct photo. I'll try to get some screen captures tonight. Anyone else have similar experience? Anyone know if there's some theoretical limit to iPhoto event & library sizes? We've probably got a library more like a pro photographer but are only basic power camera users (for reference, we shoot in primarily raw format with our Olympus E-510, and SHQ digital with anything else). Our library as said is around 190GB/19,000 photos organized into events by month (with about 10-15 other specific events) spanning the last 6 fulll years (so 60-70 events) is this a graphics/RAM issue? a couple of variables that I'm not sure of. For reference, machine is a late 2012 27" as seen below.