Turning off ModificationWatcher

I'm experimenting with Wicket inside Google's new Java support for its App
Engine. My simple apps run fine if the configuration is set to DEPLOYMENT,
however in development mode, I get an exception related to
ModificationWatcher. Looking at the exception I think this
ModificationWatcher is being used as part of a new thread which is a no-no
inside the App Engine sandbox. Is there way way to just disbable this
modification watcher without putting the entire app in deployment mode?
There are a number of items I like about development mode but this one
glitch is preventing me from using it.

Matt