caching issue related only to IE

I'm caching viewlets per every user on my website. The first session
created on internet explorer is the cache that displays for every user
after that.
On IE:
User A logs in, and sees their cached data A, user A logs out.
Then user B logs in, and sees cached data A, user B logs out.
Then user C logs in, and sees cached data A, user C logs out. And so
on...

On firefox and chrome, users see their correct data.

In order for IE to display the correct data, i can delete temporary
internet files, refresh the page and correct data is displayed.