When I use a python code block in a document any export-as-html results in the error "Invalid file-name". Without a code block the export goes without a hitch. Other exports work no probs such as export-as-ascii. The code block within the document acts as expected, it is only the export that fails. I was on org7.5 but updated to 7.8.03 but have the same result.
Also, it is only the python code blocks that fail, others work.