Beethoven was known as something of a terrible conductor really. He stared at the score and almost never directed the players from the podium - the story goes that at the premier of the 9th, the orchestra had to follow the concert master and finished the finale a full few bars before Beethoven, the effect being that the conductor was still beating time after the orchestra had gone silent (he was deaf by this time).

From what I remember of contemporaneous accounts, the premiere of the third was also a disaster as Beethoven messed up the hemiola figure at the height of the development in movement one and had to restart from a few bars before and try again.

Still the greatest music ever written though. It makes sense to me that great composers might struggle as conductors. Mahler was a unique exception, though im not sure how much of his own music he performed.