NOTICE* call from IP Phone to X-Lite

Hi, i have a Linksys SPA942 and an Softphone (X-Lite)
When i call from the softphone to the Linksys, everything is Okey. When i dial from Linksys to X-Lite i get a loop messages like this…

[Dec 13 05:15:54] NOTICE[3433]: res_rtp_asterisk.c:2190 ast_rtp_read: Unknown RTP codec 126 received from ‘10.0.1.21:25586’
[Dec 13 05:15:64] NOTICE[3433]: res_rtp_asterisk.c:2190 ast_rtp_read: Unknown RTP codec 126 received from '10.0.1.21:25586’
etc…
Every 11 seconds I get a new NOTICE… why??
I’m using G711 ulaw in the Softphone because using others i get problems…

How to fix this?

What does the SIP INVITE from host 10.0.1.21 indicate that 126 is mapped to?