Dan, I learned one yesterday too. I was cutting out some sod to expand a planter bed. It had to be done with a hand spade because of the area I was working in. I had the tractor parked nearby and tossed the pieces of sod into the bucket. The only thing on the 3pt hitch was a set of pallet forks, so essentially there was no counterweight. As I kept cutting out the sod I just kept filling the bucket. Eventually the bucket was overflowing and packed with turf.
When I was done, I had an overful bucket, and was just going to park it in the garage with the full bucket (I was intending to let the grass die) because I didn't want to drive all the way over to the mulch pile to dump it. I was also tired. End of the day and that was the last project. BUT THEN the lovely Mrs_Bob becided she wanted me to dump it, and the spot was on a gentle slope. I was smart enough to have my seatbelt on! But I wore it out of habit not because I was worried about the gentle slope. Well with no counterweight on the back, uneven ground and the need to lift the bucket, I soon found myself on 2 wheels /forums/images/graemlins/blush.gif. Fortunately I lowered the bucket to stabilize the tractor, shifted into 4wd, backed up and repositioned the tractor and safely dumped the load.
We all learn. Hopefully cleaning up a little mess of oil, or just moving the tractor to a more stable spot is all we have to learn.