how do I backspace in text fields without messing up entry?

I'm running this beta on a nexus 7 w/jellybean. When I try to edit text with the stock keyboard in fields on websites (Google search, address fields, etc), text strings start copying themselves into the text at the edit cursor. This beta seems to have fixed the problem of backspacing removing various other words in the field but this one persists. that being said, this particular field in which I'm typing this I am unable to duplicate the problem. weird.