Any woodworker worth his salt would know that a bit of wd40 spray would have fixed this!
During the recent Advanced Router class (11 and 12 November 2010) in Henderson, NV we discussed ways to need plunge routers plunging and then springing back to safety position. All of us, including the instructors Steve Bace and Brian Sedgeley, are experienced woodworkers. For some uses we think the world of WD-40.
However, the consensus was that products like WD-40, originally intended to protect machined steel and electronics from moisture, attract dust and thus gum in tight-fitting sliding bearings.
The better procedure to keep bearings sliding on precisely ground rods is to physically clean away accumulated dust, gum and grime. Often use of compressed air only make the situation worse. Following a manual cleaning, the prudent approach is to use a hint of something like graphite.
Where WD-40 can be very helpful would be a situation in a moist environment where tools need to be stored for protracted lengths of time. The woodworker would apply WD-40 before storage with the understand that when the tool is needed, the WD-40 would need to be cleaned off.