make sure the WA_Globals are properly set. it sounds like you have the CMS file in a sub directory of your domain named "/CMS100/". Check that the $WAGLOBAL_Root_URL looks like:
$WAGLOBAL_Root_URL = "http://www.mydomain.com/CMS100/"
and the $WAGLOBAL_remoteRoot is set to:
$WAGLOBAL_remoteRoot = "/CMS100/";