Back button and refreh

Hi,
I'm new here.
I have a problem and a already tried to solve it with search.

Facts: My HOME page index.htm is separated on two frames: upper.htm and lower.htm
When I click on link on upper frame it opens in the same frame (so far so good).
But, when I click back button in IE to get back to HOME page it loads only partly. I mean lower frame compleat, but upper frame does not contain all of the menus. After click on refresh button in IE, page became complete (refresh on right click in frame don't work).
But again, if I run only upper.htm, it works normaly.

Any ideas?

I apologize, my english is not my bright side.