VTK 6.2.0 + Qt 5.2.1 ---> QVTKWidget causes Seg Fault

I'm trying to use QVTKWidget to show a some vtkData in a Qt GUI. Any time I create an instance of the widget ( QVTKWidget w; /*OR*/ QVTKWidget* w = new QVTKWidget; ) the program seg faults. I'm using QPluginLoader to load a plugin on the backend BUT it still seg faults if I try to create the widget from the frontend without loading a plugin. What am I doing wrong? Thanks!

Program received signal SIGSEGV, Segmentation fault.
0x00007fffeb546dfc in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
(gdb) where
#0  0x00007fffeb546dfc in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#1  0x00007ffff7dea13a in call_init (l=<optimized out>, argc=argc@entry=1, argv=argv@entry=0x7fffffffdcf8, 
    env=env@entry=0x7fffffffdd08) at dl-init.c:78
#2  0x00007ffff7dea223 in call_init (env=<optimized out>, argv=<optimized out>, argc=<optimized out>, l=<optimized out>)
    at dl-init.c:36
#3  _dl_init (main_map=0x7ffff7ffe1c8, argc=1, argv=0x7fffffffdcf8, env=0x7fffffffdd08) at dl-init.c:126
#4  0x00007ffff7ddb30a in _dl_start_user () from /lib64/ld-linux-x86-64.so.2
#5  0x0000000000000001 in ?? ()
#6  0x00007fffffffe0a4 in ?? ()
#7  0x0000000000000000 in ?? ()

CMakeLists.txt

project( qt_frontend )
cmake_minimum_required( VERSION 2.8.11 FATAL_ERROR )

set( CMAKE_INCLUDE_CURRENT_DIR ON )

find_package( Qt5Core )
find_package( Qt5Widgets )
find_package( Qt5Sql )
find_package( Qt5Gui )

find_package( VTK REQUIRED )
include( ${VTK_USE_FILE} )

...
#set vars
#add executable
...

target_link_libraries( ${PROJECT_NAME}
    ${VTK_LIBRARIES}
    ${Qt5Core_LIBRARIES}
    ${Qt5Widgets_LIBRARIES}
    ${Qt5Sql_LIBRARIES}
    ${Qt5Gui_LIBRARIES}
)