If you had not done it already I would suggest a Reset and reload of the image.bin file. At this point you have nothing to lose. If you are not using the IE 7 browser, try IE. There was a post back in the 1.56 time frame where an xml upload would not work with FireFox but that was directory naming related and there was a message. Did you look at the devices3.xml file to see if it looks intact? Starts with the xml version statement and ends with the statement. Only because it is one of those, when all else fails, try unplugging EZSrve for 15-20 seconds.
Unless someone else jumps in with a new idea, an email or call to support seems the next step if nothing above helps.