I've had issues with hard-coded ERC being dropped when I saved a modified clothing item to the library. One workaround was to modify another version of the figure in Poser and cut and paste changes to the original figure's cr2. Another thing that could work is checking "Include morphs when conforming" when saving your clothing item to the library.

Download my free stuff here: http://www.renderosity.com/homepage.php?page=2&userid=323368