iphoto keeps crashing

I recently upgraded my whole operating system. The Apple Store upgraded my system to iLife because there were so many issues I was having with other progarms. They were hoping to take care of those. Yesterday, I started scanning old photos into iPhoto. I increased the DPI so they wouldn't look so grainy or blurry in the digital rendering. The software keeps crashing and is extremely slow. All the other softwares seem to be working fine. I at best can open a picture and edit it but when I move on to the next picture. The software closes down and I have to restart it.

Any ideas what is going on here?