Regarding this, I found out in help section:

"* Update existing download 
Use this option to update an existing project. The engine will recheck the
complete structure, checking each downloaded file for any updates on the web
site '

As started it says *re-check* since the files are already there on saved
previously, looks more like its re-downloading them, then just doing a
verifiy. I know it takes a while, but looking the at the My Web Sites
(default) folder based on the size of the givin files active and sizes repoted
in Windows, I would say its re-downloading. Can you confirm this ?
It started off ok. Testing links and all so it flew though that, but shoulds't
it be just testing the time/date stamp of previously stored files, as its
clearly these ones must be re-downloading, otherwise hTtrack wouldn't display
them.