leahb and tickler,
the tx/rx issue isn't exactly as it seems. it may be 'technically' correct to connect tx from usbmini to rx on lilypad, but this is assuming that tx and rx on the usbmini are 'traced' correctly on the printed circuit board. I am here to tell you that i currently connect rx on my miniusb to rx on my lilypad and i connect tx to tx. This is the way it works on mine. (This next statement is not a slam) My only explanation is that someone made a mistake on the lilypad traces or the miniusb traces and put one of them backwards.
There are ALOT of people that have complained about this not in sync issue. One of the common replies is 'switch your tx and rx connections'. i was getting the same error when trying things the 'right' way but when i put rx to rx and tx to tx, it started working fine.
Just some food for thought. Things are not always as they seem. i havent done this, but you may want to grab a powerfull mangifying glass and see if you can follow the traces on the pcb from the rx/tx to the pins on the lilypad and the miniusb and see what pins they go to and compare that to the schematics.