Loading classes in b56

[Jose]

With previous build b50 I had beeen experiencing some problems when loading
certain classes. 

The problem is that any thread that reach some few points (half a dozen) of
my code immediately exits. 
The common circunstance of these points is that they call a constructor of a
not yet loaded class.  

I managed to solve these problems by manually loading the class before the
confilctive point with:
  
                   loadClass()


However the recipe dont works any more with b56, at least in one of these
points. 
The ClassLoader efectively load the class (no exception thrown, class object
returned), but the thread exits when accesing the class constructor or an
static field. 

Is there any test I can do to give a more precise account of the problem?