If you really have a CHLv2 (mostly red Web interface), then
1.06 was the wrong version for TFTP recovery.
1.06 is for the CHLv1 (mostly blue Web interface), which has
different hardware than CHLv2.
Due to your last firmware being 1.54, you are forced to use
a TFTP recovery with files from firmware 1.52 at least. 1.5x
updated the uboot and broke the TFTP v1.24 which is available
for the CHLv2.
See this post for a link of a TFTP package with firmware 1.53:http://forum.buffalo.nas-central.org/viewtopic.php?p=147233#p147233
Unfortunately Buffalo does NOT provide a TFTP package for
firmware > 1.5x themselfs yet.
But one can "create" its own current TFTP release by extracting
the necessary files (like Shonk did; see link above) from a current