Attachment problem with Incident queue


I tried to add attachments to ticket in Incident queue. However, the attachment is not saved as real attachment in the database. Below is what is stored in the Attachments table:

id :1109
TransactionId: 4762
Parent: 1107
MessageId: Null
Filename: NULL
ContentType: text/plain
ContentEncoding: NULL
Headers: MIME-Version: 1.0
X-Mailer: MIME-tools 5.502 (Entity 5.502)
Content-Type: text/plain
Content-Length: 0
Content: NULL

The incorrect info is the Filename is null and Content-length is 0. Also the ContentType is different.

This is the same attachment file from a ticket on Incident Report queue which has correct information.
id: 1106
TransactionId: 4756
Parent: 1104
Filename: anaconda-ks.cfg
ContentType: application/octet-stream |
ContentEncoding: none
HeadersL Subject: anaconda-ks.cfg
MIME-Version: 1.0
Content-Type: application/octet-stream; name="anaconda-ks.cfg"
X-Mailer: MIME-tools 5.502 (Entity 5.502)
Content-Disposition: inline; filename="anaconda-ks.cfg"
Content-Transfer-Encoding: base64
Content-Length: 1205
Content: (file details)

RT: 3.8.10 upgraded from 3.8.9
after upgrading, installed RTFM 2.4.3 and RTIR 2.6.0 on CENTOS 5.6.