Hello, I'm having issues transferring or calling internal extensions. My extensions are from 1000-2000 and when I try to dial one from my ip601 phone, it simply gets to 10 before stating that my can not be completed as dialed. It will not allow me to dial 10XX. I can dial the number if I pre-dial it before picking up the phone, but this still poses a problem when transferring as you can't dial the extension without the phone line being connected. Any help would be greatly appreciated.