[imp] Errors with attachments

[Jorge Izquierdo]

Helo again. I have IMP running correctly (pfffff) except when I try to add
an attachment to my messages. It shows me next messages after selecting the
file to attach and push the Attach button:

Warning: Unable to open '/tmp/phpIVaqXa' for reading: No existe tal archivo
o directorio in /usr/local/apache/htdocs/horde/imp/compose.php3 on line 910

The configuration I have (IMP 2.2.3 over PHP4.03pl1 and apache 1.3.17) in
the defaults.php3 has been created from the setup.php3 "wizard" .

Do I have to make any changes to any configuration files?

Thanks

Jorge