My younger son's MAP tests for reading have been up and down for years. Sometimes many years past his grade level, sometimes at grade level. Ask the teacher for specifics on what kinds of questions they're missing, look for patterns.
Then again, sometimes it's because they simply have stopped caring having been tested to the point of being bored, likely my youngest DS case. Kids often don't realize the ramifications of standardized tests of course and the opportunities that the results can present them.
