After Effects CS6: Cache and Reload Footage Problem

Question

After Effects CS6: Cache and Reload Footage Problem
I am having trouble getting my footage to update in an AE project. 
In an existing project, there is an image sequence in a composition.  I have saved and closed AE, modified the footage (same dimensions and qty. of frames, only the pixel data changes), and then re-launched AE and opened the project.  Though I have changed the footage, the old content still appears.
To resolve this, I have done the following:
Edit>Purge>All Memory
Edit>Purge>Image Cache Memory
Edit>Preferences>Media & Disk Cache>Empty Disk Cache
Edit>Preferences>Media & Disk Cache>Clean Database & Cache
From the Project window I've selected all footage and selected Reload
None of these got the footage to update.  I could double-click on the footage in the project bin and scrub the play head and the old footage was still displayed.
Finally I had to replace the footage with itself and that resolved the issue.
If this is operator error, lack of understanding the cache functions, or something else, I'd appreciate some assistance. I don't recall this behavior in CS 5.5, so I am guessing this is a change in CS 6.
Win 7 Pro 64bit Service Pack 1
Intel Xeon CPU X5450 @ 3.00 GHz 2.99 GHz
RAM 20 GB

Answer 1

about Illustrator and Photoshop files in CS6 especially - you should work with Ctrl/Cmd+E (Edit Original).
when in Ae and you want to change a source file, use this command on one of the layers
from the source file you wish to change (doesn't matter if its in the timeline or project window) and
your original software linked to that file will open.
when you work this way you make AE reload that file and any change after that will be seen back in AE immediately.
it is also very convenient way to work because there can be no confusion on which file you are on
if you work with multiple source files for example.
even if you made the change with your Photoshop/Illustrator opened file and got back to Ae
and didn't see any change - press on one of the layers Ctrl/Cmd+E and this will refresh it immediately.
This is the case in CS6.
in CC I have noticed that any change I make is refreshed immediately in Ae as if it rechecks the changes all the time,
and didn't even need to use Ctrl/Cmd+E but it's a good habit all the same.
didn't come across a case where that didn't work for be but
if all fails you could always change the folder location of the file, let Ae lose it, then replace footage of the file,
and thus let Ae re-link it back.