Pictures not showing on timeline

I started a project with both video clips and added photos to it.  Everythi8ng seemed to be working fine.  I changed the time that some of the photos appear on the screen - still everything seemed to be working fine.  Today I started working on the project again - and my photos do not appear on the timeline in Expert mode - but the DO play on the screen when I play the video.  I need to get these phots in sync with my music track - so need to change more time they stay on scrren - but I can't see them to select them.  I have to go to Quick mode and then the photos appear on the time line - then I have to select the clip in Quick mode - but Quick mode won't let me change the time they stay on screen - so then I have to go back t Expert mode and change the time.  There are a lot of clips to do this way - too cumbersome - especially since it USED TO WORK in EXPERT mode.  Anyone have any ideas what is happening?  New to Premiere - so I could be doing something very wrong.  Using Elements 15

Thanks