Hey, we have a problem to upload files by FTP, the rise is cut in half or leave errors, and permits and sizes are well configured, it may be happening?
It is quite hard to suggest anything for sure since we don't have exact errors you get.
First of all check that this domain does not violate its hard disk quota limit set under Domains > domain name > Setup
You can also try increasing timeout value for ftp server: http://kb.odin.com/en/173 http://kb.odin.com/en/1533
If it does not help then post here exact errors you get and let us know what were sizes of the files you were uploading.