My CTC was really picky about USB ports when upgrading to Sailfish 7.7 - I could not get the upgrade to work on the PC I normally have connected to it. I then tried my Macbook with the same results - timeout errors when hitting the upload and reset buttons. Finally tried an old Acer laptop I have with a USB 2.0 port - worked first try.
Make sure you’re using ReplicatorG (Sailfish edition) NOT Makerbot Desktop to do the upgrade.