What did DHS know, and when did they know it?

Steve at Carpetbagger finds a nugget in the London/Glasgow car bomb story that hasn't gotten much attention:

As ABCNews.com reported, U.S. law enforcement officials received intelligence reports two weeks ago warning of terror attacks in Glasgow and Prague, the Czech Republic, against "airport infrastructure and aircraft."

The warnings apparently never reached officials in Scotland, who said this weekend they had received "no advance intelligence" that Glasgow might be a target.

Homeland Security Secretary Chertoff declined to comment specifically on the report today, but said "everything that we get is shared virtually instantaneously with our counterparts in Britain and vice versa."

Well, now, that's comforting; it's the August 6 PDB all over again. Do they not open e-mail or read faxes in Glasgow? Or did DHS really share the intelligence with the UK and Czechs? If anybody other than Joe Lieberman was chairing the committee overseeing Homeland Security, I'd suggest an inquiry into the matter. Under the circumstances, though, it hardly seems likely to occur.