montanojeff@msn.com

I went to start my car one day and turned the key over. The dash lights flickered on and off and did not turn over. I tried several time with the same result, nothing, just like the battery was dead. The battery is fine. The next day it started but I did not drive it for fear I would get stuck. I turned it over that day 6 time and it started.
I drove it the next day, stopped, turned the ignition off and on and it semed to be fine. I made 4 stops but on the 5th I had the same problem. I checked all the fuses, pulling them out and putting them back in. Then I remembered 3 years ago there is a cable that malfunctioned, detached, when I use my shifter which was not letting the engine start, this was fixed. So I moved the shifter from park to reverse, drive, 2nd, and so on back and forth several times and finally it started. I don't know if that is the problem.
I did some reading and it said a bad common battery ground could cause this problem. The day before this problem first started I had disconnected the ground cable to the battery. Using a metel wrench I hit the positive and sparked. I thought It was a blown fuse problem but there good.
I checked to see if the ground to the battery was tight and it was. I have driven it for 2 days without any problems but am worried I will get stranded again.
Could this be caused by the ground cable being of for 12 hours?
Could it be the shifter?
Could it be I shorted somthing out?
Any ideas?

Thanks,
Jeff