ma.median: cannot perform reduce with flexible type

Consider the following snippet:

``` python
import numpy as np
import numpy.ma as ma

x = np.zeros((10,))
ma.median(x, axis=None)
```

The last line throws a

``` python
TypeError: cannot perform reduce with flexible type
```

using version 1.9.1, but works with versions prior to 1.9.0 (i didn't try 1.9.0).  Is this expected behavior?

Many thanks
