ImageIo read erreur Unable to create temporary file

Bonjour

Je rencontre l'erreur suivante, auriez vous une idee ? Merci
http://192.168.17.2:80/infodev/ima-c...20un%20nom%20b...
Unable to create temporary file
java.lang.SecurityException: Unable to create temporary file
at java.io.File.checkAndCreate(Unknown Source)
at java.io.File.createTempFile(Unknown Source)
at javax.imageio.stream.FileCacheImageInputStream.<init>(Unknown
Source)
at
com.sun.imageio.spi.InputStreamImageInputStreamSpi.createInputStreamInstanc*e(Unknown
Source)
at javax.imageio.ImageIO.createImageInputStream(Unknown Source)
at javax.imageio.ImageIO.read(Unknown Source)

cela le fait egalement avec un nom court, mon applet est signée.

Merci
Philippe