Viewer pane freeze in FTP with jpg (v 10.5.7.0)

Quite often with FTP while looking through a list of jpg images, Opus will freeze with the viewer pane saying "loading...". Even when files are <1mb. It will usually hang for several minutes but sometimes it goes to a white screen and I have to kill dopus. Here's the FTP log:

--> PASV 227 Entering Passive Mode (69,163,144,228,181,165). --> RETR P1050416.jpg 150 Opening BINARY mode data connection for P1050416.jpg (199084 bytes) 196608 bytes received in 0.156 seconds (1230.480 Kbytes/sec) 226 Transfer complete --> PASV 227 Entering Passive Mode (69,163,144,228,165,224). --> RETR P1050417.jpg 150 Opening BINARY mode data connection for P1050417.jpg (289608 bytes) 226 Transfer complete ** CloseFile NO FD_CLOSE Response from Server ** 360448 bytes received in 71.651 seconds (4.904 Kbytes/sec) Connection closed
This example froze just after the last "226 Transfer Complete" message, waited about 5 minutes, then gave the closefile message.