Once changes were complete, you would either save (for new files) or resave the working file.

Correct the errors, resave the file and resubmit.

If not, you will have to reopen the files and then resave them for CP/M; check your manual.

Be sure to click on the "How to Save Your Inventory" button before you resave your file to get complete instructions.

You can get partly around that by saving a copy of the image as a TIFF, which you can edit safely, or by making all your modifications at once so you resave the file only once.

I bring in my images already optimized and CS5 will resave and change the name of the image whether you like it or not, so I'm forced to open the zip file, change the name of my good images to match the ones Indesign created and replace them.