Help!!! J30 Battery Install

[driverdriver]

The battery on my J30 completely died today. Went out and bought a replacement battery and tried to install it. I've done many battery installs before but none on the J. This is my question/problem, when I installed the cables I went with positive first and then negative, however I had to abort the negative cable installation due to sparking. On my second try I did the opposite, installing positive first and then negative, however I still got some major sparking when I brought the cable over so I had to abort again.

When I took out the original battery (3 or 4 years old and completely dead) I uninstalled it by removing the negative cable first and than the positive cable.

The new battery is of the proper , size, voltage, etc.

I've checked and made sure nothng is "on" in the car.

What am I doing wrong? Help!