recv_fd() failed

[ftp21]

Hello,
Sometimes in a mine server i receive this error and the webserver doing down

2012-02-23 18:04:18.356 [WARN] Intercomm event: 17, abnormal.
2012-02-23 18:04:18.356 [ERROR] recv_fd() failed, fd: -1, len: 0, errno: 11.
2012-02-23 18:04:18.356 [WARN] call nio_read() to clear pending data, ret: 0, errno: 11.
2012-02-23 18:04:18.356 [WARN] Intercomm event: 17, abnormal.

I need to restart LS and everything working good.

I'm using LS 4.1.10.

How i can fix this problem?

Waiting for your reply.