The <sphere> tag url accepts full urls, because of that I was able to integrate the krpano viewer into a Drupal site, where user can upload the main image and it displays in a krpano viewer. Unfortunately the <left> <front> <right> <back> <up> <down> tags that are inside the <tablet> tag (I imagine its the same for mobile), don't accept full urls, they don't even accept 'relative' urls. They need the filepath directly from the place the xml is at, I tried '../..' to go back a few directories, but that didn't work (what I meant by relative urls). For me its impossible to have the images in the same directory as the xml file, because that file is generated on the fly, something like krpano/%/krpano.xml (the % variable in my case is the drupal node id).
Can someone please help out? This would be a killer feature and would allow integration not only in Drupal but other major CMS, giving krpano an edge over other panorama viewers. If someone helps me solve this, I promkise to write a detailed tutorial on how I integrated krpano with Drupal.