I had to reset my premiere settings to fix an issue I was having and I reset my keyboard shortcuts. I had the 'Up Arrow' & 'Down Arrow' keys set to select next and previous keyframe in the effects controls panel - as well as the 'Up Arrow' & 'Down Arrow' selecting the next clip in the timeline.
When I try to add the 'select the next clip' command to the up arrow, it replaces the command for next keyframe, and vice versa.
I've been using these settings for about 4 years now and I can't imagine not being able to do this again, but I for the life of me CANNOT figure out how to set this up again.
Use Ctrl+Alt+K to bring up the Keyboard Shortcuts dialog and use the drop down menu named Keyboard Layout Preset to see if your settings are threre. Look for [Custom] if you never saved the settings you did.