I've also had problems downloading and have not positively identified the cause, but this is what worked for me:
-- I tried different speed settings, with no luck.
-- I tried a different computer, with no luck.
-- I tried moving to a different room, that seemed to help a little (probably RFI interference).
-- I tried an older version of Meade software, that seemd to help a bit too.

So, what finally worked for me is:
Another computer (WinXp) in a separate room with all electronic/electrical devices off and an old version of Meade AutoUpdate.

M.M.