Smarty error: problem writing temporary file

Hi.

I'm trying to execute a very simple Smarty project on my server:

foo.php
--------------------------------------------------
$Smarty_class_path = "/home/my_project/smartylibs/Smarty.class.php";
require_once($Smarty_class_path);
$template = new Smarty;
$template->compile_dir = "/home/my_project/templates_c";
$template->template_dir = "/home/my_project/templates";
$template->display("foo.tpl");
----------------------------------------------------

foo.tpl
-------------------
HELLO
-------------------

But I get this error message, and no "HELLO" message:
-------------------
Warning: Smarty error: problem writing temporary file
'/home/my_project/templates_c/wrt4469af176498c' in
/home/my_project/smartylibs/Smarty.class.php on line 1095

Warning: fetch(): Unable to access
/home/my_project/templates_c/%%FD^FDD^FDD1139B%%foo.tpl.php in
/home/my_project/smartylibs/Smarty.class.php on line 1258

Warning:
fetch(/home/my_project/templates_c/%%FD^FDD^FDD1139B%%foo.tpl.php):
failed to open stream: No such file or directory in
/home/my_project/smartylibs/Smarty.class.php on line 1258

Warning: fetch(): Failed opening
'/home/my_project/templates_c/%%FD^FDD^FDD1139B%%foo.tpl.php' for
inclusion (include_path='.:/usr/share/pear') in
/home/my_project/smartylibs/Smarty.class.php on line 1258
-----------------------

'/home/my_project/templates_c/' is owned by 'nobody' user, and whith
777 permissions

The same code runs ok on my local PC. Does anybody know any clue in
order to know what I
am doing wrong? Thank you very much.

You might also need to consider the permissions no /home/my_project
directory.