There is a good posting on the Real Climate blog about the IPCC AR4 blow back that is happening.  I think this gets to the heart of it:

To those familiar with the science and the IPCC’s work, the current
media discussion is in large part simply absurd and surreal.
Journalists who have never even peeked into the IPCC report are now
outraged that one wrong number appears on page 493 of Volume 2. We’ve
met TV teams coming to film a report on the IPCC reports’ errors, who
were astonished when they held one of the heavy volumes in hand, having
never even seen it. They told us frankly that they had no way to make
their own judgment; they could only report what they were being told
about it. And there are well-organized lobby forces
with proper PR skills that make sure these journalists are being told
the “right” story. That explains why some media stories about what is
supposedly said in the IPCC reports can easily be falsified simply by
opening the report and reading. Unfortunately, as a broad-based
volunteer effort with only minimal organizational structure the IPCC is
not in a good position to rapidly counter misinformation.