reconnecting offline images to an external HD

I think the issue has risen from my adding new external HD's to replace those that were full. I would transfer images from the old HD to a new one and name the new HD the same as the old one, e.g. "photo masters."

The problem is, that you copied the original image files manually to the new drive using the Finder and did not let Aperture relocate the ordinal files.

Try, if reconnecting the online images will help. See this section of the Aperture User Manual, the paragraph "Reconnecting Missing or Offline Referenced Images":

http://documentation.apple.com/en/aperture/usermanual/index.html#chapter=5%26sec tion=16

To reconnect an offline referenced image

1. Reconnect the hard disk holding the referenced image’s master, or otherwise locate or make the file available to Aperture for reconnecting.
2. Select the project that contains the offline image you want to reconnect, or select the offline image in the Browser.
3. Choose File > Locate Referenced Files.
4. If necessary, click the Show Reconnect Options button.
5. At the top of the dialog, select the file path for the master that you want to reconnect.A thumbnail of the image and some identifying metadata appear.
6. In the bottom half of the dialog, navigate to the location of the referenced image’s master on the hard disk and select the master.You can follow the file path listed for a selected image in the top of the dialog.When you select the file, a thumbnail of the image and metadata appear, allowing you to compare them to the thumbnail and metadata in the upper part of the dialog to make sure you’ve selected the correct file.
7. Click Reconnect to reconnect a specific image, or click Reconnect All to reconnect all selected images.