USB Error?

Hi. I’m trying to get GnuRadio working using USRP. I’ve managed to get
all the software installed as required. However, when I run I get noise and nothing else on all channels. Both the
GUI version and the no_gui version do this with the GUI version showing
no clear peaks on any frequencies. After a few seconds, the whole thing
seems to crash and I get a message saying "fusb: (rd status -71)
Protocol error. I first installed everything on a machine using a
Slackware distro of Linux. Since I did not have root access on this
machine, I reinstalled everything on a fresh machine using Fedora 5. I
get the exact same problem on both machines.

Does anyone have a clue what is going wrong. Any help would be much