There are a couple of minor bugs that I know of (and probably many 
more that I haven't discovered yet) in the original thesis, though 
they have been fixed in the papers on those topics.  Here are the ones 
I know of:

   1. In Section 7.2, the value given for e (the valuation of the 
      radius of a certain disk) in the case c is congruent to 1 mod 32 
      is given as 27/14.  This is wrong; I believe the correct value 
      is 26/7.  I would not be surprised if some of the other 
      calculations in this section had some minor bugs.  However, I'm 
      reasonably confident that the "moral of the story", Table 7.1, 
      is correct.

   2. The proofs of the Propositions in Chapter 8 are just wrong.  
      The results are correct, though; they've been fixed in my paper, 
      "Reduction, dynamics, and Julia sets of rational functions" in 
      The Journal of Number Theory.

I also know the proofs in chapter 5 are extraordinarily ugly; my apologies
to anyone who's actually read through them carefully.

-RLB