Eh? You're going to have to give us more info than that. Do you get an error message on Newzleech tab? Are you using 0.28.3? Does the NZB download, but isn't added to queue (in which case open in Notepad to see what's what)? Are you able to access
http://www.newzleech.com via browser?
Newzleech is working fine here ... but is slow.
Edit: it seems that Newzleech site is currently being ddos'ed again.