I attempted the upgrade with the engine running in order to prevent the upgrade from failing. I also did a low-level format using the SDFormatter application prior to installing the new firmware on it. I know the card works because I had used it in the camera for the whole of the previous day without any issues.
I attempted the upgrade to v1.011E from a freshly-formatted, brand new, SanDisk Ultra 32GB SD Card.
The camera worked perfectly and I was able to format SD cards directly from within the camera. Prior to the upgrade, I was running v1.009E of the firmware with no issues at all. I attempted to upgrade the firmware on my DR500GW-HD yesterday but the upgrade seems to have failed and, worryingly, something more severe appears to have gone wrong with the camera as a result.