Untouchable JPEG

I have a set of JPEG files that contain a medical slide against a white background. Parts of the slide have lines drawn across reaching the white background. These lines are then labeled. I want to remove the label, for studying purposes. I know I can use whiteout to do this, but I’m doing it in PSCS as it’s neater.

I can erase all the labels on all the slides, bar one. It’s a slide containing a cross-section of a spleen, and everytime I try and use the eraser (or any brush tool) it errors with "Cannot complete your request because of program error" The slide is a normal JPEG. I’ve even tried creating another layer, and working on that instead, but it gives the same error. I’ve looked at it closely, and it does not resemble currency 🙂 What gives – and BTW, if I could duplicate this, it would make all of my commercial JPEGS untouchable, which would be great for copyright. If anyone wants a go at it, tell me where to put it, so that you can download.