after cache using php : forum freezed !!

[abdobasha2004]

I added a plugin with this code to global start :
$cache_expire = 60*60*24*365;
header("Pragma: public");
header("Cache-Control: maxage=".$cache_expire);
header('Expires: '.gmdate('D, d M Y H:i:s', time()+$cache_expire).' GMT');

It was to cache some files but it did not work so I deleted it
since then some pages of my forum seem freezed: time in footer stopped at 4:06 and no new threads added to forumdisplay !!

can anybody help !