Comment 6 for bug 572447

Looks like this is caused by the addition of SSE-instruction acceleration of strcpy() on AMD64 in libc6.
syslogd was using strcpy() to shift a string forward (to eliminate leading whitespace), but this is not allowed per the ANSI standard. By chance, the old libc6 worked fine, but the new accelerated libc6 does not.

It has been fixed in Debian, but the fix didn't make it into Maverick.