Can't assign a sum'ed series to a dataframe
Using pandas 0.11, there appears to be a bug (or at least non-intuitive behavior) when setting a sum on a dataframe. Any advice?

p = pandas.DataFrame({ 'x' : [1,2,3], 'y' : [1,2,3] })
sumOfP = p.sum() #Gives a Series of [6,6]. OK.
totals = pandas.DataFrame({ 'someOtherSeries' : [1,2])
totals['sumOfP'] = sumOfP #BAD! This is now [nan, nan]

I'd expect totals['sumOfP'] to be [6,6]. So why is it nan,nan?
