I've just glanced (fast) through the problem book and I wanted to send
you a note telling you that I think it is wonderful. It really seems
enticing, rich, friendly, and vastly interesting. About the 144169
problem, there was a bit of discussion about it and related things
last Spring (Kevin Buzzard, and Robert Pollack, in particular, had
ideas).  The more general question behind the 144169 example is to
consider 
 the p-adic (Hida) Hecke algebra (say, of tame
level 1, for starters) as a 
-algebra and to form D =
discriminant of the finite flat 
-algebra 
, so that 
 is
in 
 (i.e., is an Iwasawa function). We want to know something
about the basic invariants of 
, e.g., its "
-invariant " in
each of the 
 discs that form the rigid-analytic space underlying
 and more specifically, we want to know something
about the placement of the zeroes of 
, if there are any.  With
p=144169 and the 24th disc, since that part of 
 is quadratic over
that part of 
, there could be some zeroes, so the question is:
are there some, and how many?  If I remember right, Kevin had an idea
about how to quickly compute this and Pollack had an idea of how--in
the context of some tame level--to get examples for low primes like
 and 
, where 
 has some zeroes.