I have a LAB I use in my class that works with BT4 R2. I have tried it with BT5 and it did not work. I found this thread and issue that I thought my be close, although this issue shows fixed, my problem still exists.
Backtrack 5 - Bug #45: etterlog doesn't extract passwords from *.eci file - Redmine
What I do in my lab is start Ettercap get a list of servers, select the FTP server as target 1 and the host system accessing the FTP server as target 2. I start ARP poisoning and start Ettercap's sniffing. I log into the FTP server from the host and in BT4 R2 the Ettercap message window shows the user name and password. The message window does not show the user name and password in BT5 or BT5 R1. Is there something I can do to get this to work, or must I wait for a fix?