Bitmap Pattern Can not be Seen

I have an image - .png file that i want to use as a pattern fill. I have:-

1. Clipped it to remove the parts that I do not want
2. Duplicated it 3 more times
3. Arranged it into a 2x2 square that is seamlessly tileable
4. Converted it to a pattern.

When I fill an object with this pattern, it appears white - you cannot see the fill. Only when I drag the object do I see the fill. Then as soon as I release the mouse button, the fill disappears again. It does not export either - Is this to do with the fact that I have clipped it?

Hmmm, nice bug. Think it probably is the clip. Exporting the 2x2 and reimporting it would probably get round it for now, can you file a bug on it in the tracker?