I've got an HD2 running the Nexus 1 software. I used to be able to use screenshot it, but can't anymore

I downloaded the app that Sombre posted up a little while ago, but it seems to not have worked. When I try click on "other" then profile, it says "connection to phone cannot be established: No device attached to USB" What did I do wrong? I have my phone set up to allow the USB debugging, or whatever it's called. Any help/info is MUCH appreciated, thanks!