I am having the same problem getting the "invalid answer" error at various download complete percentages. I purchased the MX800 in May of 2005 and initially performed numerous downloads while fine tuning all the devices' macros without errors. I recently made a minor modification to the file and am now getting the "invalid answer" errors. I can sometimes click OK and the download continues and then fails at 100%. I then remove the AAA cells for a reset and the changes seem to have taken effect.
I am not able to perform the live update function successfullyeither, as it begins to download from the site and then gets a "download failed" error. Any Ideas?