Hey Dave,
Thanks for the reply. I am using CC 2014. I think I may have figured it out.
So for years, After effects auto reloads your footage if it has been updated (you stomp over a piece of footage and AE sees that and reloads without a prompt). For the last few iterations it has an auto loading feature where if your sequence of frames or footage is being added upon (more frames in the sequence show up) AE will continue to find and load that sequence without a manual reload footage click in your bin. Its kind of handy except when you are dealing with lots of 32 bit EXRs or some other large file sequence and it will bog things down as it is constantly searching for and loading any new footage.
I dont have AE on this computer but it looks like the option to turn it off can be found here:
“Go to After Effects > Preferences > Previews… (for Macs) or Edit > Preferences > Previews… (for PCs).
Import…
Under Automatic Footage Reloading, you will find a drop down for Auto Reload. The manual completely fails to tell us how to use this setting. You have two choices, both of which are valid. If you are working in Premiere Pro, Encore, Photoshop, etc., simultaneously, and want to make changes to the footage itself, it will automatically reload and appear in After Effects.”