FigureCanvasQTAgg has no 'renderer' error in v1.1, works in v1.0.1

Hello --

When I run the following code (heavily adapted from the matplotlib examples):

SCHistogram = Figure(figsize=(6,6), dpi=300, facecolor='w') # 6 inches across (X-axis) by 4 inches tall (Y-axis)
ax = SCHistogram.add_subplot(111)

canvas = FigureCanvas(SCHistogram)

AxisTitleFontProps = FontProperties(size=10, family='serif')

n, bins, patches = ax.hist(DimensionData)

y = normpdf( bins, self.meanVal, self.stdDev)
line, = ax.plot(bins, y, 'r--')

ax.set_xlabel(self.Description, fontproperties=AxisTitleFontProps)
ax.set_ylabel('Number of Parts' ,fontproperties=AxisTitleFontProps)
ax.set_xlim([x_lowest, x_highest])

AxisTickFontProps = copy.deepcopy(AxisTitleFontProps)


s = canvas.tostring_rgb() # save this and convert to bitmap as needed

The following error appears when run under matplotlib 1.1 (the code successfully completes in v1.0.1):

Traceback (most recent call last):
  File "./analyze.pyw", line 681, in fileGenerateReport
  File "/Users/engelsma/dev/SPC_Analyzer/trunk/1.0.10/", line 201, in Generate
  File "/Users/engelsma/dev/SPC_Analyzer/trunk/1.0.10/", line 318, in CreateHistogram
    s = canvas.tostring_rgb() # save this and convert to bitmap as needed
  File "/Users/engelsma/.virtualenvs/cmm/lib/python2.7/site-packages/matplotlib/backends/", line 418, in tostring_rgb
    return self.renderer.tostring_rgb()
AttributeError: 'FigureCanvasQTAgg' object has no attribute 'renderer'

Any ideas as to why this code fails under v1.1? I've checked the changelog and I see nothing that would cause this problem...

Thanks in advance,

Dave Engelsma