Yes, I've experience the same problem.  I believe my breaker is a 55amp.  I have a 1973 C-172M.  I've had a new breaker installed as we thought the old breaker might have weakened after all these years.  That was a wasted effort.  Lately i've learned my landing light is a 250 watt which draws more current than the one designed. 

Have you check the actual individual loads on the alternator?  I bought my plane two years ago, and I'm still learning about and what may or may not be the designed loads.