I've been attempting to update my NVS2500. Following the directions included with the update, I put the file in the root of the hard drive. Then going into the device menu, I selected "Firmware Update" and almost immediately received a "CRC ERROR" prompt.
I have formatted the hard drive and tried updating from different memory sources. This device was purchased in Korea in late 2009. The US Representative that I spoke with said that the origin and date may have something to do with the issue, but he could not offer any other help.