#REF error on shared spreadsheet

Every so often some of my excel sheet references are turning to #REF. Its not all of them, and it always happens that the bottom of my page gets the #REFs first. I have a macro set up to open another excel file and update its references (from a website), and then close. I have it open and give it a 10 sec timer to stay open. Would it be possible, that its not getting fully updated in that amount of time (occationally) and thats why the top of the page info usually stays good and the lower have gets the #REF errors?

Anyone had a similar issue?