Blocking 'SIP/904-0820db78', already blocked by thread -1228

sorry for my english!

I have the same problem with asterisk 1.4:

Thread -1228571728 Blocking ‘SIP/904-0820db78’, already blocked by thread -1228325968 in procedure ast_waitfor_nandfds

the PlayDtmfAction is ok and response of managerApi is:

message=‘DTMF successfully queued’; response=‘Success’

Nothing for the operation

Have you got a solution ?

Thanks for help !!!