Originally Posted by troyb

To those having peformance problems when OmniWeb is loading a new page. Try going into your OmniWeb application support folder and remove the file called "HistoryIndex.ox"

It appears that this has a negative effect on performance if it gets too big and gets accessed each time you add a new page to your history.

Complete file path:

~/Library/Application Support/OmniWeb 5/HistoryIndex.ox