We've been working through a problem recently where largish uploads of files would reliably fail - but not in the way you'd expect. A typical course of events would be:
- Client uploads file via SSH, SFTP or FTP
- Upload might drop out a couple of times during the process, but resume OK - or might not have any dropouts
- Upload finishes. Client & server confirm checksum of uploaded file - it doesn't match, so then retries the upload again
- Repeat ad infinitum.
Our particular problem was with Storage Craft Image Manager uploading images to a remote server....