Holy Cow, Phoenix09!!!!
I've been following this thread because we too have been losing IE's history. Did all the repair and update stuff to no avail of course. Looked at your suggestion re the 'days to keep pages in history' hasn't reset itself to 0 and had a look. IT SHOWED ZERO DAYS!!!
Just how the heck did this happen?!?!
Anyway many thanks.
A thought for Globaliser: do you have Zonealarm Pro cos theres a option under 'privacy' to clean history. Worth a try.