[tim]

Interessant ist aber, daß viele z.B. einen 180° falschen AUF als "nicht gelöst" empfinden...

Was sind die Argumente, die ein U2 als gelöst rechtfertigen?

Die derzeitigen Regeln?

1.) Irrelevant, weil "als "nicht gelöst" empfinden".
2.)

10d) All pieces of a puzzle must be fully attached to the puzzle, and in their required positions. Exceptions: see Article 5 Puzzle defects.
10e) A puzzle is solved when all face colours are reconstructed and all the parts are aligned within certain limits.

• 10e1) For each two adjacent parts (for example two parallel adjacent slices of a cube) of the puzzle that are misaligned more than the limit described in Article 10f, these two parts are considered to need one move to be solved (Half Turn Metric).
  

10f) Limits of misalignment for puzzles:

• cube shaped puzzles: =< 45 degrees
  

Ein U2 wird dagegen "solved with penalty" genannt:

10e3) If one move is needed, the puzzle is considered solved with a penalty of 2 seconds.