This is only for the Chart problem. My other problems can you read here
under RadGrid Forum.
I have solved my own problem with RadChart.
The solution is as follows:
On RadGrid there is a property UseSession.
set UseSession = false.
Second property that has to be changed is TempImageFolder.
Set the path to this folder.Folder name can be what ever you like.
TempImageFolder must be in you ASP.NET Website application location.
Then you need to set permissions for ASPNET account on the folder. ASPNET account must have writable permission.
I have set it to Full Permission.
Now it work in IE8 and IE7.
I hope this post will help others that can have a similar problem out there.