To some problems in update of awstats report of some domains the problem is corrected with:

In whm Basic cpanel/whm setup update the option Apache Access Log Style to combined

In httpd.conf of domain in question comment the line TransferLog ... and add:
CustomLog domlogs/DOMAIN.COM combined

I wait to have contributed

In portuguese:
Para alguns problemas na atualizacao do awstats para alguns dominios o problema pode ser corrigido com:

No whm Basic cpanel/whm setup altere a opçao Apache Access Log Style para combined

No httdp.conf do dominio em questão comente a linha TransferLog ... e adicione:
CustomLog domlogs/DOMINIO.COM.BR combined.

Espero ter contribuído!

att,
Marcelo