Does it matter that there are 0-byte resources in my compiled SWC?

Question

I have a Flex 3 SWC file compiled using the compc Ant task. It looks very similar to the one generated by the Eclipse export release build command, but there are some 0-byte files in the mx packages that unnerve me:

Archive:  flex/package/bin/package.swc
  Length     Date   Time    Name
 --------    ----   ----    ----
        0  10-16-08 12:59   mx/controls/NumericStepper.png
     4741  10-16-08 12:59   locale/en_US/rpc.properties
     1222  10-30-08 22:27   locale/en_US/core.properties
     1130  10-30-08 22:27   locale/en_US/formatters.properties
        0  10-16-08 12:59   mx/containers/ControlBar.png
     6460  10-16-08 12:59   locale/en_US/messaging.properties
        0  10-16-08 12:59   mx/controls/Spacer.png
     3170  10-30-08 22:27   locale/en_US/controls.properties
      641  10-30-08 22:27   locale/en_US/effects.properties
      962  10-16-08 13:00   locale/en_US/logging.properties
        0  10-16-08 12:59   mx/controls/List.png
        0  10-16-08 12:59   mx/controls/Tree.png
        0  10-16-08 12:59   mx/containers/HBox.png
        0  10-16-08 12:59   mx/controls/Button.png
   334062  09-09-09 09:34   catalog.xml
        0  10-16-08 12:59   mx/controls/VScrollBar.png
        0  10-16-08 12:59   mx/containers/Box.png
      638  10-30-08 22:27   locale/en_US/containers.properties
     1091  10-30-08 22:27   locale/en_US/SharedResources.properties
        0  10-16-08 12:59   mx/controls/HScrollBar.png
        0  10-16-08 12:59   mx/controls/TextArea.png
      518  10-30-08 22:27   locale/en_US/skins.properties
        0  10-16-08 12:59   mx/controls/ProgressBar.png
     5251  09-08-09 12:44   package/assets/success.png
   847017  09-09-09 09:34   library.swf
     1572  10-30-08 22:27   locale/en_US/collections.properties
        0  10-16-08 12:59   mx/controls/Label.png
      315  09-08-09 12:44   package/assets/folder.png
        0  10-16-08 12:59   mx/controls/TextInput.png
      504  10-30-08 22:27   locale/en_US/styles.properties
        0  10-16-08 12:59   mx/containers/TitleWindow.png

It seems to me that these files should not even be included in this archive, much less as 0-byte files. Is this a valid archive, or do I need to fix my build rules somehow?