I had lots of grief with this... It stopped working in the middle of a convention. I think something corrupted the software.
Do the webOS doctor thing version webos-internals.org/wiki/Webos_Doctor_Versions
Follow this guy's instructions when you do it... (copied from another blog)
you need to start the process in recovery mode.
Remove battery and disconnect phone from PC.
Start osDoctor and follow prompts until it tells you to connect phone.
with battery removed, hold up-volume on phone and plug it in to pc
when the big question mark shows up, continue to hold down the button and insert the battery
when the USB symbol appears on the phone, release the button.
it will verify charge level before continuing, so that could take up to 15 minutes before it will continue.
And that will take care of it.
Now this is critical. When the phone starts up, it will try to log into your profile. DON'T DO IT. Create a NEW profile. (The old one has a corrupted backup.)
And now you have a new phone. (Minor pain, you have to reset up your email etc.. ) USB stuff is still there.