The problem happens in NetBeans IDE, but just on 1.5, so it is believe it is a general problem of the implementation.

It has been reported as a bug
http://www.netbeans.org/issues/show_bug.cgi?id=50423
follow the link to get more details.

I saw the same problem also with other dialogs (e.g. the New File
wizard). In most cases, it was reproduced on a remotely connected
Linux desktop, but it was reproduced also on a local desktop.

The symptoms are exactly the same as the symptoms of JDK bug #5097241
- "None of the comps in FileDlg receive keyevents on Solaris9 (CDE)
with XToolkit" (see
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5097241).


I succeed with debugging the problem. It seems to be caused by code that is designed to delay keystrokes until a component is focused probably to prevent keystrokes to be delivered to wrong window (as far as I know it is new to 1.5). Sometimes the code gets confused, probably by the dialog not receiving focus.
 
Here is a snapshot from my debugging session at the moment when a typed key is being processed (and is refused):
http://www.netbeans.org/issues/showattachment.cgi?attach_id=18475
###@###.### 10/25/04 16:13 GMT