Can someone please explain to me why is this program CE? Delphi compiles it OK. Is it MLE?

type
  TPok=^TElem;
  TElem=record
          i,j:integer;
          next:TPok
        end;
var
  a:array[1..1000,1..1000] of char;
  t,z,p:TPok;
  i,j,m,n:integer;
begin
  assign(input,'');
  reset(input);
  readln(m,n);
  z:=nil;
  for i:=1 to m do
    begin
      for j:=1 to n do
        begin
          read(a[i,j]);
          if (a[i,j]='.') and (z=nil) then
            begin
              new(z);;
              z.i:=i;
              z.j:=j;
              z.next:=nil;
              a[i,j]:='0'
            end;
        end;
      readln
    end;
  close(input);
  t:=z;
  while t<>nil do
  begin
    i:=t^.i;
    j:=t^.j;
    if a[i-1,j]='.' then
      begin
        new(p);
        p.i:=i-1;
        p.j:=j;
        p.next:=nil;
        z.next:=p;
        z:=p;
        a[i-1,j]:='0'
      end;
    if a[i+1,j]='.' then
      begin
        new(p);
        p.i:=i+1;
        p.j:=j;
        p.next:=nil;
        z.next:=p;
        z:=p;
        a[i+1,j]:='0'
      end;
    if a[i,j-1]='.' then
      begin
        new(p);
        p.i:=i;
        p.j:=j-1;
        p.next:=nil;
        z.next:=p;
        z:=p;
        a[i,j-1]:='0'
      end;
    if a[i,j+1]='.' then
      begin
        new(p);
        p.i:=i;
        p.j:=j+1;
        p.next:=nil;
        z.next:=p;
        z:=p;
        a[i,j+1]:='0'
      end;
    p:=t;
    t:=t^.next;
    if p<>z then
      dispose(p)
  end;
  a[z^.i,z^.j]:=chr(0);
  t:=z;
  while t<>nil do
  begin
    i:=t^.i;
    j:=t^.j;
    if a[i-1,j]='0' then
      begin
        new(p);
        p.i:=i-1;
        p.j:=j;
        p.next:=nil;
        z.next:=p;
        z:=p;
        a[i-1,j]:=chr(ord(a[i,j])+1)
      end;
    if a[i+1,j]='0' then
      begin
        new(p);
        p.i:=i+1;
        p.j:=j;
        p.next:=nil;
        z.next:=p;
        z:=p;
        a[i+1,j]:=chr(ord(a[i,j])+1)
      end;
    if a[i,j-1]='0' then
      begin
        new(p);
        p.i:=i;
        p.j:=j-1;
        p.next:=nil;
        z.next:=p;
        z:=p;
        a[i,j-1]:=chr(ord(a[i,j])+1)
      end;
    if a[i,j+1]='0' then
      begin
        new(p);
        p.i:=i;
        p.j:=j+1;
        p.next:=nil;
        z.next:=p;
        z:=p;
        a[i,j+1]:=chr(ord(a[i,j])+1)
      end;
    p:=t;
    t:=t^.next;
    if p<>z then
      dispose(p)
  end;
  writeln(ord(a[z^.i,z^.j]))
end.

They use strange Delphi compiler (I think it's Delphi 2.0), so you should use it too to be absolutely sure your program shouldn't receive CE. In fact there are a few main differences between Delphi 2 and Delphi 7:
- integer is 16 bit, not 32;
- dynamic arrays are not allowed to use;
- problems with dymamic lists' compiling (your problem!) - just try to compile the text with Turbo Pascal 7 and change the text in a proper way - and your will receive WA(3).

P.S. Fixed text - WA(3):

type
TPok=^TElem;
TElem=record
i,j:integer;
next:TPok
end;
var
a:array[1..1000,1..1000] of char;
t,z,p:TPok;
i,j,m,n:integer;
begin
assign(input,'');
reset(input);
readln(m,n);
z:=nil;
for i:=1 to m do
begin
for j:=1 to n do
begin
read(a[i,j]);
if (a[i,j]='.') and (z=nil) then
begin
new(z);;
z^.i:=i;
z^.j:=j;
z^.next:=nil;
a[i,j]:='0'
end;
end;
readln
end;
close(input);
t:=z;
while t<>nil do
begin
i:=t^.i;
j:=t^.j;
if a[i-1,j]='.' then
begin
new(p);
p^.i:=i-1;
p^.j:=j;
p^.next:=nil;
z^.next:=p;
z:=p;
a[i-1,j]:='0'
end;
if a[i+1,j]='.' then
begin
new(p);
p^.i:=i+1;
p^.j:=j;
p^.next:=nil;
z^.next:=p;
z:=p;
a[i+1,j]:='0'
end;
if a[i,j-1]='.' then
begin
new(p);
p^.i:=i;
p^.j:=j-1;
p^.next:=nil;
z^.next:=p;
z:=p;
a[i,j-1]:='0'
end;
if a[i,j+1]='.' then
begin
new(p);
p^.i:=i;
p^.j:=j+1;
p^.next:=nil;
z^.next:=p;
z:=p;
a[i,j+1]:='0'
end;
p:=t;
t:=t^.next;
if p<>z then
dispose(p)
end;
a[z^.i,z^.j]:=chr(0);
t:=z;
while t<>nil do
begin
i:=t^.i;
j:=t^.j;
if a[i-1,j]='0' then
begin
new(p);
p^.i:=i-1;
p^.j:=j;
p^.next:=nil;
z^.next:=p;
z:=p;
a[i-1,j]:=chr(ord(a[i,j])+1)
end;
if a[i+1,j]='0' then
begin
new(p);
p^.i:=i+1;
p^.j:=j;
p^.next:=nil;
z^.next:=p;
z:=p;
a[i+1,j]:=chr(ord(a[i,j])+1)
end;
if a[i,j-1]='0' then
begin
new(p);
p^.i:=i;
p^.j:=j-1;
p^.next:=nil;
z^.next:=p;
z:=p;
a[i,j-1]:=chr(ord(a[i,j])+1)
end;
if a[i,j+1]='0' then
begin
new(p);
p^.i:=i;
p^.j:=j+1;
p^.next:=nil;
z^.next:=p;
z:=p;
a[i,j+1]:=chr(ord(a[i,j])+1)
end;
p:=t;
t:=t^.next;
if p<>z then
dispose(p)
end;
writeln(ord(a[z^.i,z^.j]))
end.

Compiler is FreePascal. See http://www.freepascal.org for detailed documentation.
Main features:
- 8-bit shortint and byte
- 16-bit smallint and word
- 32-bit integer, longint and longword
- 64-bit int64
- 255-byte strings by default
- long Delphi strings if use {$H+} directive
- dynamic arrays are not allowed
- result variable work like in Delphi
- more strict syntax than in Delphi

Thanks very much

BTW, why the information about compilers is not mentioned on this site?