Having managed to get through the nomadic rift cavern and to the treadmill, I used it and found that no characters received a speed increase, even though the highest speed any character had was 30. I dropped a beacon there and tried coming back to it. Still didn't work. Tried exiting the game, then starting up again and using the beacon to get there. I got the message just fine, but the stat boost never came. I haven't tried the other stat boosters, and I suppose they could work. I also haven't tried the circus, because it hasn't come around yet. Although if one stat booster doesn't work it seems to me like none of them will.

Anyone have any guesses as to what the problem is?

Edit: Oh, the stat bonuses appear after resting. I could have sworn I had rested after, but I guess I didn't.

Yeah, you need to rest before they'll show up... this confused me the first time also. In addition, I don't think you can raise your stats above 50 at those locations.