This isn't something I never noticed, but rather an interesting bit of trivia I had to find out on my own:

On October 11, 2004, there was a completed strip that was not put up due to current events. The Giant later mentioned that it might find its way into a compilation book, but I figured it was something he simply forgot about. But that's because I misread and thought he meant it was an alternate version of #110, possibly containing a Superman reference (Christopher Reeve died the previous day). Then it dawned upon me that he was referring to bonus strip #109a, which contains the line "Yeah, he's totally paralyzed. It's cool." So, yeah, unfortunate timing but good move by the Giant.

The more you know.