Front port USB drive static problem please help

So I recently opened up my case to macgyver an old 500GB external Hard Drive inside my PC that i built last month. Didn't really think it would be much of problem so I did it in my dorm room on the floor instead of in the basement like I usually do (my room does have a carpet). I figured it would be fine since I wasn't ever touching the Mobo and I touched the case from time to time to discharge any static built up. So I got everything installed and closed it all up, booted it up and it posted fine and loaded Windows 7. Everything was running fine and dandy, I got the HD all set up, removed those annoying pre-installed features and all my files and everything were there.

Now this is when the fun starts. I needed to sync my iTunes up with my iPod (since all my music was on the external) and so i went to plug the iPod connection wire into the front USB port (my case, a coolermaster 922, has 2 usb ports, a SATA port, and the mic/headphones port on the front). Now the cable didn't have anything attached to it (my ipod was over on my tv stand) but when the plug metal contacted the USB port metal my screen notified me that it wasn't receiving any input and went into standby. No blue screen or anything. Confused by this, I went around to inspect the back thinking the HDMI cable had fallen out or something and when i touched the back of the case I got a static shock (this may be because I was sitting down and acquired static when I stood up or something, just thought it was worth noting).

Concerned, I turned off the PC and rebooted. I did get a screen informing me that windows did not shut down properly and gave me some safe mode options but I started the PC up normally and everything loaded back up fine. Now I would like to let you guys know that this entire time my wireless keyboard/mouse combo was plugged in to the other front USB port (it uses one logitech usb thingie for both) and it was functioning without issue. Intrigued, I plugged it into the other port that caused the crash and it worked perfectly fine. I placed it back in its original usb port and proceeded to plug the iPod cord in again, which caused another "crash" as soon as the metal contacted. I again rebooted my pc, more concerned, but again it rebooted just fine without issue. I also tried plugging it in the back port which went without incident and worked just fine. Because I am either stubborn or an idiot (one of the two, probably both) I decided I was going to try plugging in the USB cord in the front again. This time it worked perfectly fine! Huzzah! success! and now my ipod is currently syncing to my iTunes.

So I have a couple questions:
1. What the heck was causing the problem? could it be the HD i just installed? The environment I was in when I installed it? The iPod cable shorting out?

2. Will there be any permanent damage to my system? As far as I can tell it is now working just fine without a hitch.

Anyways thanks for your time and I know for sure its down to the basement every time with this puppy whenever I have to open it.

edit: one additional note = I also tried plugging in another usb cable and it also produced a crash. So I plugged in a total of four times, with the fourth time being the time it worked. Also, the first time was the only time i received a shock.