PROBLEM WITH COOKIES

On the list page of "Sales Returns", sometimes not showing data. This happened after I clicked the "Detail Links" on list page of"Sales Item".

But when after logout - login, I immediately open the list page "Sales Returns", all data appears.
I also experienced the following problems:

After I did the addition of sales returns, I see that the list of items that I would add is not in accordance with what I choose when filling out the form added sales returns. This happened after I clicked the "Detail Links" on the list page of sale items.
Maybe my problem occurs because the app store "cookies" primary key sales item. So when I open another table that also reference the primary key selling items, then sell the items that appear are selling items stored primary key.

Or there may be causes other than cookies? Please instructions.
In Fact, I do not coding any store session variable associated with the primary key sales item.
How do I resolve the problem?
Could when I open another page that references the primary key item on sale, are not affected by my actions earlier?