The whole network driver cache management paradigm was redone for 2.4, and I've often wondered whether the same potential problem exists, but never had the time to go in and check.
There, I've mentioned it. My conscience is clear. ;o)
*blush* Okaay, I....I need to clear my conscience too. I knew about this when posting, but forgot to mention it. Brian, you may find that the + 2 for IP alignment does not work precisely for the reason Kevin mentioned. You may need to cache align your RX buffer. Again, let us know what you discover. Okay, now MY conscience is clear.
-Steve