Natural logarithms of large numbers



In wxMaxima 0.7.6 + Maxima 5.16.3 I get the following sequence:

  (%i1) log(10^308), numer;
  (%o1) 709.1962086421661
  (%i2) log(10^309), numer;
  Maxima encountered a Lisp error:
   Error in SETQ [or a callee]: Can't print a non-number.
  Automatically continuing.
  To reenable the Lisp debugger set *debugger-hook* to nil.
  (%i3) log(10^308)+log(10), numer;
  (%o3) 711.4987937351601
  (%i4)  

Have I reached some strange boundary here?  Is there a way to move the
boundary upward (say to 10^400) instead of breaking the calculation into
pieces?  
-- George Leeman