Supress error 500 by baiduspider

Hello.

Since recent upgrade of mod_fastcgi I keep getting this:

FastCGI: client stopped connection before send body completed
FastCGI: client stopped connection before send body completed
Handler for fastcgi-script returned invalid result code 53

This is caused by baiduspider and ancient IEs. It seems that they
close the socket before server could send the data. This result in
error 500.

Could you please help me suppress this error (I don't want to see it
in access.log as I get an email for every such an error) while still
logging the event in error.log?