AppEngine Date field editing

When you have a Java Date field in the AppEngine JDO and try to enter the new value using Google Web interface:

Data Viewer -> Edit Entity or Create an Entity

you may be getting this error: "Could not instantiate int: invalid literal"

I think this is a bug, as this field should be a Date not an int, but there is a simple work-around:

1) change the int to null, then save

2) change the null to gd:when and you can enter a date in the format 2009-07-29 20:36:17.565000