RBPi Doesn't Boot With GPS GPIO Board Attached

[Reza Nikoopour]

Hello,

I'm currently building an NTP server using the following set up:

Raspberry Pi B+ <
http://www.amazon.com/gp/product/B00LPESRUK/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
>
Raspberry PI GPS Add-on <
http://imall.iteadstudio.com/raspberry-pi-gps-add-on.html >
FreeBSD 10.1 built with CrochetBSD

I was able to build an img with Crochet and get the Pi to boot into a
shell.  However, whenever I booting the Pi with the GPS board attached it
will not boot.

When I plug in the GPS Add-on into the GPIO connector, my Pi fails to boot
before starting the kernel.  It boots to the point where it says "Press
enter to prevent auto boot" and then the letter 'L' shows up and starts
erasing text from the screen.

I was initially using a 1.5A power supply.  It was suggested to me to try
using a stronger power supply so I tried a 2.1A power supply, but that
didn't work either.  Using the 2.1A power supply resulted in the same boot
problem described above.

Next I tried using Raspbian to boot the Pi, but a similar problem
occurred.  The Pi boots without the GPS board attached.  When the GPS board
is attached, it boots kernel and when the screen to start Raspbian Software
Configuration then the following message prints to the screen indefinitely:

SysRq : HELP : loglevel(0-9) reboot(b) crash(c) terminate-all-tasks(e)
memory-full-oom-kill(f) kill-all-tasks(i) thaw-filesystem(j) sak(k)
show-memory-usage(m) nice-all-RT-tasks(n) poweroff(o) show-registers(p)
show-all-timers(q) unraw(r) sync(s) show-task-states(t) unmount(u)
show-blocked-test(w)

Could I get some guidance with fixing this problem?

Thanks!
Reza