I've seen possible allusions to this problem in other discussions but haven't found it addressed directly. I'm running Moodle 1.5 on linux and have my upload_max_filesize set at 8M.
I cannot get any powerpoint file over 2M to open successfully. In IE, the window hangs for awhile then gives a 'file not found' error. In Firefox, the file downloads but I then get an error that it cannot be opened. All files less than 2M open great - everything over has this problem.
I can open the large files successfully on my hard drive before I load them. I can load them successfully using Moodle (so the 8M max upload seems okay). I can also link directly to them in the data directory and they open fine there. It's only when I am clicking on the resource link and going through file.php that it fails.
Any ideas? I've seen the suggestion to convert large ppt to flash, but until our developers can get to that point?