Is this still an issue? If yes, anything to do upstream? Markus -- Markus Neteler <neteler fbk eu> http://mpa.fbk.eu/markus/ FBK-irst - Centro per la Ricerca Scientifica e Tecnologica MPBA - Predictive Models for Biol. & Environ. Data Analysis Via Sommarive, 18 - 38050 Povo (Trento), Italy