It may be worth checking all the getters in class Sheet to ensure that either: - they return a valid type - document that the expected behaviour is for callers to expect exceptions be raised if there is no valid setting. My apologies if this is documented and I've just missed it.
The javadoc documentation has significantly improved since this bug was reported. Please evaluate the latest version available at http://poi.apache.org/apidocs/index.html Also, you are advised to try the latest POI-3.5-beta4 or download daily builds from http://encore.torchbox.com/poi-svn-build/ Yegor