images on the page category and on the product page does not appear

I have a serious problem I can not solve, product images do not appear, nor within the product itself.

however it has some strange quirks like image appears perfectly on the home, inside the product thumbnail in the sidebar and when I click to enlarge within the product.

the following prints:
Error: Attachment 38054

homepage: Attachment 38055

Single Product page:Attachment 38056

Single Product:Attachment 38057

The odd thing was that it worked before and besides I’ve tried various forms of change in the case of placeholders, but nothing worked. follow this link but nothing solved the problem: http://turnkeye.com/blog/magento-images-not-showing/

Thank outset, it is urgent