File sizes and memory
The PHP.ini file is set to allow max upload and post sizes to 20MB. So that shouldnt be an issue. As for the memory, it is on a hosted server at Godaddy, so the memory limit is set at 32MB...
Here is somthing I just noticed tho....we are able to get larger files to upload on the sites where we have more bandwidth....so, it almost seems like it is a timeout issue, where the larger files take longer when uplaoding accross the slower (384 MB UP DSL) links or ones that may have more traffic at the time of the upload. That could just be coincidence however, but just a thought...
For the files, it seems that generally anything 5MB an under always goes through. If they get bigger (and none are bigger than 8MB), then they sometimes 500 error out and other times (sometimes) go through.