Our daughter (age 7 - 2nd grade) fails tests on reading comprehension, when she is asked to read a book on her own. Her teacher has brought it to our attention and is baffled at our daughter's poor scores.

As background on our daughter:
-she loves to read and always has a book
-she is in an advanced program and gets straight A's
-she scored 152 IQ and 99.9 academic
-She is social, has good friends, and makes friends easily
-She likes to please and is never in any trouble

But....

-She makes 'sloppy' mistakes when taking tests (not paying enough attention to the question)

-She appears to need more guidance/support than average (again, if she is reading to someone and getting feedback, she is fine, but if she is on her own, she bombs)

-And, when faced with a new test/event (of any kind, be it school, play, et cetera), she is very reluctant/timid. She typically does very poorly the first time on everything. Then, once she 'gets the lay of the land', she gains confidence and blows the doors off.

So, are we dealing with insecurity? Or, are we dealing with lack of concentration? Or, something else?

And, what do we do to help her?