Consider the following trivial class

@myobj/myobj.m

function f = myobj(str)
  f.name = str;
  f = class(f,'myobj');

@myobj/display.m

function display(f)
  fprintf('%s\n',f.name);

@myobj/transpose.m

function f = transpose(g)
  % do interesting things with input ...
  f = builtin('transpose',g);

Now, lets make an array of these ...

GNU Octave, version 3.5.90+
Copyright (C) 2011 John W. Eaton and others.
:

octave:1> p = myobj('foo')
foo
octave:2> q = myobj('bar')
bar
octave:3> a = [p q]
foo
bar
octave:4> size(a)
ans =

   1   2

octave:5> class(a)
ans = myobj
octave:6> b = a.'
error:   ../@myobj/transpose.m at line 3, column 3
error:   ../@myobj/transpose.m at line 3, column 3
 :
(and lots more of these)

It seems that the builtin array transpose is not "seen"
in the overloaded transpose method for the object, so it
calls itself again and again until some kind of recursion
depth is exceeded.

The same code runs fine on Matlab

                           < M A T L A B (R) >
                  Copyright 1984-2011 The MathWorks, Inc.
                    R2011b (7.13.0.564) 64-bit (glnxa64)
                              August 13, 2011

>> p = myobj('foo')
foo
>> q = myobj('bar')
bar
>> a = [p q]
foo
bar
>> size(a)

ans =

     1     2

>> b = a.'
foo
bar
>> size(b)

ans =

     2     1

Similar problems arise with other array methods (eg vertcat)