Some places are a little tricky for throwing teleporter stones on top of, and can depend on where you are standing as well as where you are trying to drop. If you check the
screen shot (127KB) I made on how to get out of the easter egg area if you brought both teleporter stones with you, I played around for awhile in the eastern section (below the teleporter pad), then moved around a bit and found a place that worked.
For throwing things long distance, have you tried waving the cursor around the screen, so see if a slightly different location will help? I did this a few times moving chests of loot.