As I posted yesterday on a like thread...
Did this judge lose his clearance?
He can give any reason why he quit and the government may not be at liberty to discuss the basis for his removal.
Did Valerie Plame retire or did she loose her clearance?
Also, remember all the 'rat spokespersons asking why President Bush didn't get a warrant from this court, especially since the requests are almost always OK'd and don't take any more than 15 minutes to get. (The 15 minutes stuff is probably BS, but they were saying it.)
IMO there may have been very good reasons to circumvent this particular judge and possibly a couple others too.
Speed and secrecy often are all important in taking down a dangerous cell. This guy has undermined our efforts to defeat al Qaeda all along the line. They may have been afraid he'd tip al Qaeda off. (Or maybe WaPo or NYT--OK, all part of the same effort.)