In theory, if you go here:http://www.digitalnetworksna.com/support/rio/product.asp?prodID=100
You should be able to download the 1.10 firmware.
Be warned: use the smaller of the two files, the one that says no CDDB update included. At some point in the past (and possibly today as well) the larger file was corrupted.
If you successfully download the smaller file and it doesn't seem to work for you, perhaps you just don't know what you're doing with ISO files. You have to know how to burn ISO files. Most of the time, when people complain about how the image doesn't work for them, that's why: They didn't use the ISO file correctly.
You can't just drop the ISO file onto a CDR. That's not how you use them. You have to burn the ISO as an *image*. That's a different procedure. Check the documentation that comes with your CD burner software to learn how to burn an ISO image.