Uploading Slides to Chameleon

It seems that not many applications support the default pptx file extension from Microsoft Office 2007 including the Chameleon website. I had to convert the file to an earlier version to upload my slides. During my visit to the website, I noticed that I couldn't preview my slides nor previously downloaded slides. I think that if the preview function worked properly, it would make the site much more enjoyable as many users like to screen images prior to downloading the full size image. Also, my files took extremely long to upload. Maybe it's their server or maybe it's time for me to subscribe to FTTH. 5Mbps upload speed for the win!