I've notice a problem when Excel when I first click on the Excel icon in Home. It open a new tab showing Excel WebApp, then I set the filename to enable auto save. Later when I click around the different Worksheet, in Sheet3 it will keep going to the end of the cell, it went as far as WXW for columns, and millions of rows. Nothing wrong with Sheet1 and Sheet2. After switching back and forth between Sheet1 and 3, the problem still persist. It resolved after I've close and reopen the file. 

Now if I do the same again, by creating a new excel file, it won't happen anymore.

Also, the 4 new document buttons does nothing if I click on them (They're suppose to create new document, excel, powerpoint or onenote), at http://*.sharepoint.com/TeamSite/Documents/Forms/AllItems.aspx

Faulty,

Have you had the same issues using Internet Explorer 8 (or 9) or Firefox? Typically Chrome works for OWA (Outlook Web Access) Lite only.

Bruce,

I just tested with IE8, it's the same for the new document icons at TeamSite\Documents