Beantownsbest ?
I tried it with my secret key by removing the 2 last letters and it worked. Are you sure in step 2 you selected HEX and you got step 3 correct? E.g. If the result is 0x3EA1 you need to turn it into A13E before attaching to the long hex.
It's a bit tricky, it took me 4-5 tries until I got it right.
EDIT: Actually, if it lets you into the account viewer then this is the secret key with the correct checksum. It would report an incorrect key otherwise. I'm just afraid now that you saved the wrong key ?