Can't receive Fax Unsupported SDP media.. etc

Hi to all,
it is my first post here, i’m a new user of asterisk, i’ve searched on internet for my problem but i’ve not find nothing…

I’ve Asterisk 1.4.18, i’m tryng to receive fax on my estension with support t38, the trunk is with sip protocol and support t38.

When my estension try to receive fax i have this error:
[Nov 14 13:11:05] WARNING[3176]: chan_sip.c:12114 handle_response_invite: RTP re-invite after T38 session not handled yet !
[Nov 14 13:11:07] WARNING[3176]: chan_sip.c:5085 process_sdp: Unsupported SDP media type in offer: image 5005 udptl t38
[Nov 14 13:11:07] WARNING[3176]: chan_sip.c:14076 handle_request_invite: RTP re-invite after T38 session not handled yet !
== Spawn extension (mor, 0122675118, 9) exited non-zero on ‘SIP/fastalpfax_02-0821f100’
– Got SIP response 503 “Unavailable” back from XX.XX.XX.XX
[Nov 14 13:12:28] WARNING[3176]: chan_sip.c:1947 retrans_pkt: Maximum retries exceeded on transmission 301ac5bc367361d25d5759303a865067@ for seqno 801 (Critical Response)

I’ve read a lot of posts on internet but i don’t known what i’ve to do… Can anyone suggest me how to do for resolve so… Or How i can read something ?

Thanks for all