Unfortunately, the other side is fried from my first attempt at switching a cog, when I didnt know that the lockring was reverse threaded... I got it off alright, but killed that side of the hub obviously.
Due to this incident, I have taken it easy / deliberately with the other side...
Please let me know if you see anything wrong with my install ation procedure:

1. Screw on cog / mount on bike / tighten by jumping on the pedals...
2. Remove wheel, screw lockring on counter clockwise (by hand until it meets the cog)
3. Tighten lockring with lockring tool
4. Ride around, tighten lockring (repeat)

Seems logical to me... did I forget anything?
I always know when the lockring isnt tight after I change a cog cause I can feel it slip when I try to skid... IS THIS THE PROBLEM?

...from skidding when the lockring isnt tight enough initially? Is that little bit of high torque back spin from the cog enough to strip the lockring threads on the hub a little?

I havent felt it slip at all lately and like I said, I am constantly decelerating and skip stopping when riding here in in city traffic...

CRAP... Crap. Im gonna have to buy a new wheel tomorrow.