Ran a JavaFX app from NetBeans 7.2 dev environment and got the attached stack trace in the output window when I resized my application window.
It is reproducible, but doesn't happen on every resize.
I have attached a ZIP of the NetBeans project.
To reproduce:
1. compile and run the project from NetBeans 7.2 running with JDK 7u6 b22
2. Click "Load word list" and choose the "sample_words.txt" file
3. Click "Create Game Board" - wait
4. When the letter grid appears it will be too large and cut off the status bar area. Grab the lower left corder and make the window larger
- that should trigger this stack trace:


2012-08-03 10:51:39.942 java[22721:707] unrecognized type is -2
2012-08-03 10:51:39.942 java[22721:707] *** Assertion failure in -[NSEvent _initWithCGSEvent:eventRef:], /SourceCache/AppKit/AppKit-1187/AppKit.subproj/NSEvent.m:1348
2012-08-03 10:51:39.943 java[22721:707] Invalid parameter not satisfying: cgsEvent.type > 0 && cgsEvent.type <= kCGSLastEventType
2012-08-03 10:51:39.945 java[22721:707] (
0 CoreFoundation 0x00007fff8fdf2716 __exceptionPreprocess + 198
1 libobjc.A.dylib 0x00007fff925f6470 objc_exception_throw + 43
2 CoreFoundation 0x00007fff8fdf2558 +[NSException raise:format:arguments:] + 104
3 Foundation 0x00007fff920e5962 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 189
4 AppKit 0x00007fff8b36bd2c -[NSEvent _initWithCGSEvent:eventRef:] + 2782
5 AppKit 0x00007fff8b5e9d9a +[NSEvent eventWithCGEvent:] + 243
6 libglass.dylib 0x000000015ef5f00f listenTouchEvents + 31
7 CoreGraphics 0x00007fff8c17ba91 processEventTapData + 150
8 CoreGraphics 0x00007fff8c17b8e4 _CGYPostEventTapData + 189
9 CoreGraphics 0x00007fff8c422a65 _XPostEventTapData + 107
10 CoreGraphics 0x00007fff8c422b5d CGYEventTap_server + 106
11 CoreGraphics 0x00007fff8c17b9d2 eventTapMessageHandler + 30
12 CoreFoundation 0x00007fff8fd61b50 __CFMachPortPerform + 288
13 CoreFoundation 0x00007fff8fd61a19 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 41
14 CoreFoundation 0x00007fff8fd61759 __CFRunLoopDoSource1 + 153
15 CoreFoundation 0x00007fff8fd948bf __CFRunLoopRun + 1775
16 CoreFoundation 0x00007fff8fd93dd2 CFRunLoopRunSpecific + 290
17 HIToolbox 0x00007fff8cb38774 RunCurrentEventLoopInMode + 209
18 HIToolbox 0x00007fff8cb38512 ReceiveNextEventCommon + 356
19 HIToolbox 0x00007fff8cb383a3 BlockUntilNextEventMatchingListInMode + 62
20 AppKit 0x00007fff8b28cfa3 _DPSNextEvent + 685
21 AppKit 0x00007fff8b28c862 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 128
22 AppKit 0x00007fff8b283c03 -[NSApplication run] + 517
23 libglass.dylib 0x000000015ef4c4c9 -[GlassApplication runLoop:] + 777
24 Foundation 0x00007fff9216b8a7 __NSThreadPerformPerform + 225
25 CoreFoundation 0x00007fff8fd71841 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
26 CoreFoundation 0x00007fff8fd71165 __CFRunLoopDoSources0 + 245
27 CoreFoundation 0x00007fff8fd944e5 __CFRunLoopRun + 789
28 CoreFoundation 0x00007fff8fd93dd2 CFRunLoopRunSpecific + 290
29 java 0x0000000100a004bc CreateExecutionEnvironment + 871
30 java 0x00000001009facac JLI_Launch + 1952
31 java 0x0000000100a00819 main + 101
32 java 0x00000001009fa504 start + 52
33 ??? 0x0000000000000006 0x0 + 6
)