Here is a solution if you ever get the error message below.
It might be related to me upgrading mysql from 4.0 to 4.1.
When restarting cpanel it gives.
Starting eximstats: DBI connect('eximstats:localhost','eximstats',...) failed: Client does not support authentication protocol requested by server; consider upgrading MySQL client at /usr/local/cpanel/bin/eximstats line 264 Can't Connect at /usr/local/cpanel/bin/eximstats line 267.
This is probably due to mysql being upgraded by still using the old version of the DBI and DBD::mysql perl modules.
Now try restart cpanel ( /etc/init.d/cpanel restart )
cpan> get DBD::mysql
(This should download the DBD module
$ cd /home/.cpan/build or cd /root/.cpan/build
$ cd DBD-mysql-3.0002
$ perl Makefile.PL
$ make && make install
No more eximstats error
Hope this can help someone