I suggest (sorry, more reading) that you read this thread, it might help. Sometimes it appears that using a stripped UBoot factory image helps:
When you go back to the original firmware, you must use the TPLink's image, or the FriedZombie images that are UBoot stripped.
Edit: I've noticed that FriedZombie seems to be down. You can make your own stripped version using the dd linux command (or dd for Windows) by following the ToH Doc:
Then, make sure when you offer your file via TFTP that it is correctly spelled (it's also case sensitive). Disable any firewall on your station offering the file via TPTF.
Maybe you can manage to use the serial port without soldering. If your serial port holes are empy, try to coin the wires using toothpicks (slice the toothpick in half using a knife if too big).
