Flex Library Build Path - Include all classes from all source paths

The other day I started a new gig and I was having an issue with some Flex Library Projects.  These projects were originally created in Flex Builder 3 and then recently imported into Flash Builder 4.  The issue I was having was with the Flex Library Build Path.  The "Include all classes from all source paths" option would not stick between opening and closing Eclipse.

I dealt with this for a couple of days, but it finally got on my nerves so I decided to find the issue and fix it.
It turned out to be a simple fix.  The version attribute in the .flexLibProperties file was set to 1.

I guess when converting these flex lib projects from Flex Builder 3 to Flash Builder 4, the version never got updated.  In Flash Builder 4, the version number should be set to 3.

Updating the version attribute to 3 fixed the issue.  The include all classes from all source paths worked now between closing and opening Eclipse.

-Dan