I went and bought the jtag cable you recommended and I'm using the precompiled software.
I'm getting the same issue. I've checked my soldering (I've soldered many of pin headers) and it looks fine.
here's what I'm getting.
JTAG Tools 0.6
Copyright (C) 2002, 2003 ETC s.r.o.
JTAG Tools is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
There is absolutely no warranty for JTAG Tools.
Warning: JTAG Tools may damage your hardware! Type "quit" to exit!
Type "help" for help.
jtag> cable parallel 0x378 WIGGLER
Initializing Macraigor Wiggler JTAG Cable on parallel port at 0x378
detect does nothing.