[exim] mailx with exim 4.60 doesn't strip Bcc: headers?

I'm using Exim 4.60 and I sent out an e-mail with mailx.
This program invokes exim as "send-mail -i <recipients>" and includes a Bcc:
header.

strace:
execve("/usr/sbin/sendmail", ["send-mail", "-i", "jpdalbec"], [/* 22 vars */])

However, the Bcc: headers were not stripped from the e-mail. Has anyone else
seen this problem?
Thanks,
John Dalbec