I started looking last night - knew it was series 4 or 5, but I skipped "Bad Blood" because I just KNEW it wasn't that one.
Had a very nice time reviewing "Causalities of War" and then had to watch "Plan of Attack to get The Man back on the job, even though I knew it wasn't the lightbulb one. 
It's amazing how fast you can get through episodes when you only watch the bits with MK in them. Of course, hitting replay when he looks especially cute slows it down again...
J