Procmail filter sometimes failed...

Hi for all,
In my procmailrc i have this lines in the file.

:0 H
*^Content-type: (multipart/mixed)
{

    :0 B
     *^Content-Disposition: (attachment|inline)
     *filename=".*\.(ocx|ade|adp|bas|bat|chm|cmd|com|cpl|crt|dll|exe|eml|hlp|hta|htt|inf|ins|isn|isp|js|jse|lnk|mdb|mde|msc|msi|msp|mst|pcd|pif|reg|sc|scr|sct|shb|shs|vb|vbe|vbs|pps|pptx|ppsx|ppt|wsc|wsf|wma|wmv|avi|mp3|mp4|mpeg|mpg|mov|qiv|asf|mpe|wsh)"
     {
        :0
        /var/mail/attach
     }

}

if something attach is found, the e-mail will to /var/mail/attach
so, some e-mails, like one today (one with pps extension), pass
trought this rule.
is something wrong ? with this rule... thanks.