>To reproduce:
>
>1. Open www.eetasoft.ee/ieframe/main.htm in IE 6
>2. Wait until right frame is loaded and table appears. It is more than
>1 MB, so it takes some time.
>3. Scroll right frame down a number of lines.
>Do'nt scroll to the end of table.
>4. Observed result:
>
>Left and right frame rows horizontal positions are different.
>The difference between rows increases for every page moved.
>But if you move to the end of table, all is suddenly OK.
>
>See www.eetasoft.ee/ieframe/observed.jpg
>
>5. Expected result:
>left and right frame row positions must be same.
>
>How to fix this ?

Your headers doesnt have the same height in both frames.
The difference increase at each new header row you insert.