hoe to fix a mail problem

i get this errors in mail.log:
Aug 12 14:38:47 atom037 postfix/master[25433]: warning: process /usr/lib/postfix/cleanup pid 25441 exit status 1
Aug 12 14:38:47 atom037 postfix/master[25433]: warning: /usr/lib/postfix/cleanup: bad command startup -- throttling
Aug 12 14:39:47 atom037 postfix/cleanup[25957]: fatal: open dictionary: expecting "type:name" form instead of "."
Aug 12 14:39:48 atom037 postfix/master[25433]: warning: process /usr/lib/postfix/cleanup pid 25957 exit status 1
Aug 12 14:39:48 atom037 postfix/master[25433]: warning: /usr/lib/postfix/cleanup: bad command startup -- throttling

any idea?
running latest ehcp on ubuntu jaunty with all updates.