random phpXXXXX files in /tmp

[andrew morgan]

I have a working installation of IMP (imp 2.2.3, horde 1.2.3, php
4.0.3pl1).  The only minor annoyance I have is that my /tmp directory
(upload_tmp_dir) is filling up with random phpXXXXX files, like so:

[root@yt conf]# dir /tmp
total 738
drwxrwxrwt   3 root     sys          706 Dec 27 16:06 .
drwxr-xr-x  25 root     root         512 Dec 20 10:23 ..
drwxrwxrwx   2 root     root         179 Dec 18 14:45 .pcmcia
-rw-------   1 nobody   nobody         0 Dec 27 16:03 php2RaONP
-rw-------   1 nobody   nobody         0 Dec 27 16:05 php2VaiOP
-rw-------   1 nobody   nobody         0 Dec 27 16:06 phpA8ayQP
-rw-------   1 nobody   nobody         0 Dec 27 16:06 phpjXaqQP
-rw-------   1 nobody   nobody         0 Dec 27 16:05 phplZaOQP
-rw-------   1 nobody   nobody         0 Dec 27 16:04 phprfaOOP
-rw-rw-r--   1 root     sys         5224 Dec 18 14:45 ps_data
-rw-rw-r--   1 root     sys       350380 Dec 19 10:31 ups_data

A new one seems to be created whenever someone goes to the login page of
IMP.

I am using mysql for session support and I have explicitly disabled
php4's built-in session support during compile time.

Any ideas?

	Andy