An updated AntExtras plugin is available in this download package. The file name is antextras.jar
To use this updated plugin, you must replace the version of antextras.jar in the WSAD_installdir\eclipse\plugins\com.ibm.ant.extras_5.0.0\runtime with the new version.
This fix allows you to import projects multilple times. If the project already exists, then it will be refreshed.