jamesrt:ubergeeknz: Had it been replaced yet?
If not I'd suggest calling in, tell them the troubleshooting you've done and ask if a replacement unit can be sent out for you to try.
It's certainly not a common issue that you're having.
This is the "over 48 hours later" part of no response. I've asked them for a replacement unit, and haven't heard anything.
I don't believe that expecting a response within 48 hours is unreasonable attitude.
Sorry that you've not heard back... can you PM me with your username and/or ticket number, and I'll follow up for you ;)