I have a page in Confluence with two gliffy diagrams. When I try to export the page to PDF using the command under the 'Tools' button my browser loads for a few minutes then the Atlassian 'down for maintenence' screen appears and my PDF never gets generated.
When this first happened I thought Confluence had completely crashed. It turned out I was able to return to Confluence using my OnDemand url. Then continue using Confluence as usual, as long as I didn't try to export that page as a PDF.