Comment 23 for bug 802904

I think I found the issue: The preview is rendered with a maximum of 512x512 px².
I got the scaling of the preview image right, but messed up scaling of the rendering (i.e. every image is rendered unscaled up to a dimension of 512x512 px² and afterwards stretched to have the correct size in the preview area.

Unfortunately I tested only with images smaller than that yesterday and focused on viewBox stuff and the like...