Smarty

[Johny]

my Smarty Version 2.3.1 is sometimes Loading the wrong Template File.

I wasn´t able to reconstruct this problem it just happend sometimes with different templates and sites.

$smarty is initialized in a config file where also
$smarty->template_dir is set

In the main php file the templates is displayed by
$smarty->display("templatename.tpl");

But sometimes smarty displays othertemplate.tpl
deleting all ./templates_c files had the effect that smarty did display anotherwrongtemplate.tpl
$smarty->display("fullpath/templatename.tpl") did display the right template
but after changing it back smarty did display wrongtemplate again
after $smarty->display("nonexisting.tpl") returned the smarty tpl not found error and changing back to $smarty->display("tmplatename.tpl") smarty displayed the correct template again.
I know this problem sounds a bit mysterious,
the site worked correct for weeks before this Problem applyed about 4-5 times
is here anybody who had a similar problem or knows anything helpful?