Sorry I saved mid-edit...
Sun JDK 1.5.0_15
Windows Server 2003
Has anyone successfully used composite components packaged in a separate JAR file?
In case anyone else runs into this problem here's some more info I found.
According to this bug report on the Facelets site a change was made in DefaultFaceletFactory around version 1.1.13 that caused composite components to break when JAR'd and the REFRESH_PERIOD was not -1. I removed atl==0 from the check in the method needsToBeRefreshed and my component started working correctly. I'm not sure why this change was made though and don't know the side effects of removing it.
Based on another bug report I read, I'm guessing someone developed a custom resource resolver that returned a last-modified time of 0 to indicate their resource should always be refreshed.
The bug has a target milestone of 1.1.15 but wasn't fixed in version 1.1.15B2 that's bundled with Seam 2.0.3.CR2.