settings not sticking

Hi,

I have Drupal 6.10/just downloaded and installed - theme is terrific and my clients love the look. My db is continually being cleaned and purged of old mess from 5.x days and many older themes, modules... Would this affect author/date settings? I cannot hide dates and authorship for any posts - tried global and other settings... Noticed breadcrumbs are not sticking also - is this indicative of an overall issue with my install?

Thanks
Gregg