Atlas flextrack (SuperFlex 83) revisions

Apparently Atlas HO scale flextrack (specifically their code 83 Super Flex-83) has revisions. I happened to have two pieces side by side and noticed minor differences between what appears to be revisions "A" and "C".

On the underside of the track the most noticeable difference is the webbing between the ties. On "A" it is as wide as the base of the rail; on "C" it is about half as thick.  The writing has also been reformatted a bit, but the only notable change is the revision letter. The other noticeable difference is the tie thickness has changed: on "A" each tie is 2.35mm (0.0925" = 8" scale), on "C" it is 2.20mm (0.0866" = 7.5" scale). A minor difference to be sure, but it can definitely be seen when they're side by side.

The other, odder difference is on the top side. The spike detail has changed. Where it gets weird is that on one side of the track the spike detail got finer. "A" spikes are 0.75mm wide (0.0295" = 2.6" scale), but on "C" one side has finer 0.6mm (0.0236" = 2.0" scale) spikes, but the other side has clunky 0.95mm (0.0374" = 3.25" scale) spikes!

For comparison, the spikes on the classic Atlas code 100 flextrack are a massive 1.75mm (0.0689" = 6" scale) on 3.4mm (0.1339" = 11.7" scale) ties).

Has anyone else noticed this?  Any idea why they did that?  Of note, the finer spike detail is on the fixed rail and the coarser spike detail is on the sliding rail.

05-Dec-2010 update: I found some revision "B" track in my collection. It looks superficially similar to "A" track, I haven't bothered to pull out the calipers to see if any of the dimensions differ, but they look very close. I have attached a scan of both top and bottom for reference.