Motion blur in slow motion

In earlier versions of Blender (before 2.37) it was possible to create a Matrix-style effect by having objects appear to move slowly but display the motion of moving much faster, by giving them a time IPO with a low gradient. The objects would be displayed moving as though their speed had been reduced, but with their original motion blur factor. This neat effect (which is what I thought the whole point of the time IPO was) doesn’t work in 2.37 and above. Is there another way to get this effect, preferably with vector blur ?