Was the device from Australia? Also is there a provider logo display when you turn the device on?
What we can do is download the Optus 7100 firmware to your PC using this
LINK. Once downloaded you need to install the file on the same machine as BlackBerry Desktop Manager is installed on. Then rename the vendor.xml file to vendor.bak (located in C:\Program Files\Common Files\Research In Motion\AppLoader) and connect the device to your PC. When you open BlackBerry desktop manager you will be prompted with an option to upgrade the firmware.