Spurious internal error has occured

I am using DPX9 and I have been exporting pages as a commercial pdf. All works fine until I use the region rectangle tool and then the clone tool to clone an area of the image before pasting the clip back onto the image. This all works fine and is a very easy means of copying areas of an image but when I go to export as a commercial pdf I get the 'Spurious internal error has occured' and I have to restart xara before I can export anything again. Anyone have any ideas what could be causing it?

Should have added that if I delete the pasted clone and try to export I still get the same error unless I restart.

Have a good weekend.

Sean

Any effects such as this are best converted to a bitmap copy before trying to export.