RAP swt ScrolledComposite breaks in disposal while user interaction persists

Question

I have a RAP application where I am refreshing widgets and content. In all instances everything works flawlessly (sudo: class call->render content->add disposelisteners->wait for content outdated timeout->call run() to dispose previous content and redraw); however, when the client activates mouselistener on scrollbar at the same time as disposal and redraw, the scrolling of new scrollbar glitches out (attempts to scroll the window, gets about 10% scroll and freaks out and snaps back and forth between 0% and ~10%).

EDIT: Environment is win8 server running Tomcat with RAP.rwt_3.1.0

EDIT2: When shell gains focus again after run(), for one frame it looks as though to flash a native message dialog, then continues as normal. That may help someone more familiar with rap/rwt src debug.

EDIT3: happened while client actively scrolled to bottom as disposal and redraw of composites.

Stack: TypeError: Cannot read property 'getFocusRoot' of null
at Object.getFocusRoot (/rwt-resources/310/rap-client.js:11527:32)
at Object.handleFocusedChild (/rwt-resources/310/rap-client.js:5123:25)
at Object._onmouseevent_post (/rwt-resources/310/rap-client.js:15431:24)
at Object._processMouseEvent (/rwt-resources/310/rap-client.js:15409:10)
at Object._onmouseevent (/rwt-resources/310/rap-client.js:15386:14)
at HTMLBodyElement. (/rwt-resources/310/rap-client.js:624:17)

Different when actively scrolling using touchpad instead of click-drag

Stack: Error: Invalid target for ServerObject, or target not in ObjectManager
at Object.getRemoteObject (/rwt-resources/310/rap-client.js:63649:13)
at Object.getRemoteObject (/rwt-resources/310/rap-client.js:62395:45)
at Object._sendHorizontalScrolled (/rwt-resources/310/rap-client.js:52264:14)
at Object.dispatchSimpleEvent (/rwt-resources/310/rap-client.js:3831:27)
at Object.sendImmediate (/rwt-resources/310/rap-client.js:62370:14)
at Object. (/rwt-resources/310/rap-client.js:62296:12)
at Object._dispatchEvent (/rwt-resources/310/rap-client.js:3867:18)
at Object.dispatchEvent (/rwt-resources/310/rap-client.js:3808:12)
at Object._oninterval (/rwt-resources/310/rap-client.js:4481:16)
at /rwt-resources/310/rap-client.js:624:17

Found https://bugs.eclipse.org/bugs/show_bug.cgi?id=436757 suggesting maybe persistent issue when combining complexity of RWT scrollbar vs native browser scrollbar in RAP 3.0 update? (no client-side disposal of widgets left orphaned content with disposeListeners attached)