Problem to print when Mask is on

[morhug]

When i'm making my map on the composer and exporting it in jpg, png or pdf, it works well. But when i'm printing those documents, the result is bad, without the color gradient.
PDF ou JPG view.pdf

[xcaeag]

If the image is well generated, it is not a problem related to the plugin (?).
I only see the solution of correctly setting the style of the mask layer (degraded according to the shape), in the same way as another layer.