Widget locks up with certain FITS files

[pkgw]

I used the following code to fetch FITS data and attempt to show them in pywwt:

img_list = SkyView.get_images(position='SN 2011FE', survey='SwiftXRTCnt', pixels=140)
img = img_list[0]
wwt.layers.add_image_layer(img)

Upon so doing, the widget locked up. The browser debug console showed an error about name is null. So, probably some missing metadata messing things up.