Have to clear temp internet files every time

Every time I visit my site wwworkbench.com, I cannot navigate the site by clicking on links until I delete all temporary internet files.  This started last week.  I updated to 6.10 but the problem remains.  I have logged in from 3 different computers with either IE 6 or IE 7 and the problem is the same.  Any ideas?

Update.  This afternoon, the problem seems to have gone away.  I'll post again if the problem returns.