Possible issues (particularly within an individual session):
Heavy cut & paste operations
Many Preview instances
Many generate operations
Exiting too soon after a generate operation
Many DHTML operations (popups, etc.)
Imports (Word, PDF, Excel, etc.), especially with unorthodox
formatting
Many conditional tags
Shaky source control configuration
Invasive anti-virus product
Hidden network-share configurations
Feature overload (Glossary, browse sequences, drop-downs,
expanded text, image maps, etc., etc., etc.)
Good luck,
Leon