getting the AVR Dragon to work with the IDE

Hello all,

I am trying to get the avr dragon to use as a isp programmer from within the IDE and stumbeled upon a cryptic error message:

processing.app.debug.RunnerException
	at cc.arduino.packages.uploaders.SerialUploader.uploadUsingProgrammer(SerialUploader.java:242)
	at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:64)
	at processing.app.Sketch.upload(Sketch.java:1713)
	at processing.app.Sketch.exportApplet(Sketch.java:1624)
	at processing.app.Sketch.exportApplet(Sketch.java:1596)
	at processing.app.Editor$DefaultExportAppHandler.run(Editor.java:2434)
	at java.lang.Thread.run(Thread.java:745)
Caused by: processing.app.helpers.PreferencesMapException: program.pattern
	at processing.app.helpers.PreferencesMap.getOrExcept(PreferencesMap.java:258)
	at cc.arduino.packages.uploaders.SerialUploader.uploadUsingProgrammer(SerialUploader.java:236)
	... 6 more

in my programmers.txt in my hardware folder i have te following entry for the dragon:

dragonisp.name=Dragon ISP
dragonisp.communication=usb
dragonisp.protocol=dragon_isp
dragonisp.program.protocol=dragon_isp
dragonisp.program.tool=avrdude
dragonisp.program.extra_params=-Pusb

whats wrong?