Uploading a file

Are Aasenhuus are@xray.ath.cx
Mon, 20 Aug 2001 17:28:41 +0200 (CEST) 

I get the current message when I'm trying to attach a message to a mail;
Fatal error: Call to unsupported or undefined function is_uploaded_file() 
in /home/httpd/html/horde/imp/compose.php3 on line 911

I'm running IMP 2.2.6 and horde 1.2.6


Tnx

/Are