Cannot transfer between two FTP sites...

I thought it would be easy, since I'm constantly using FTP clients using a single session to upload and download files to my computers. Anyway I can connect to two completely different sessions just fine but when I try to transfer one little JPG file it just gets stuck in the queue and the only message I get is:
[15:40:45] 3>250 OK. Current directory is /public_html/data/mdelig00/files/AntMiner Files
[15:40:45] 3>PWD
[15:40:45] 3>257 "/public_html/data/mdelig00/files/AntMiner Files" is your current location
[15:40:45] 3>MLST brokenfan.jpg
[15:40:45] 3>550 Can't check for file existence
[15:40:45] The operation has been added to the Transfer Queue. Check the Transfer Queue for the status.
I've tried making the folders writable by everyone, tried different sites, and put both sides in binary mode. What am I missing here?