asterisk warning message

[ast1]

I got this warning message from asterisk cli.
Anybody has any idea why I got this message???

channel.c:2290 ast_write: Thread 1080662352 Blocking 'Local/78600051@default-3590,2', already blocked by thread 1081461072 in procedure ast_waitfor_nandfds

[mflorell]

That's usually normal from doing DTMF passthru, doesn't cause any problems.