It seems to me that some gun dealers in border states were reporting this information to the ATF, but the ATF said sell them anyway.
I believe the ATF is under tremendous political pressure from the Obama administration to find a way to regulate guns.
I believe the ATF is an organization that is in peril. The field agents know how to do they're jobs, but the upper echelon doesn't know what to do to keep theirs.
The "Gun-runner" scandal has hurt the organization's credibility, even if the media has in large part left the story alone.