(FORTUNE Magazine) – As hinted in the heading, the column you are now gaping at proved to be tougher to produce than usual. Half a dozen entries were aborted after your correspondent had spent a lot of time on them. Basic problem: The facts kept not turning out the way they were required to for the story line to work. We spent a whole lot of time, for example, on the infamous 15% pension tax that FORTUNE wrote about two months ago (December 19). This, you will recall, was the tax on ''excess distributions'' from employee benefit programs and IRAs. Our plan was to track down and identify the liberal lowlife in Congress who in the dead of night had insinuated this soak-the-rich provision into the 1986 tax reform act. Alas, it turned out that not a lot of sleuthery was required: The pension tax was in the original tax reform proposal submitted by the U.S. Treasury in 1984. To be sure, Don Regan had proposed only a 10% soak. Then it turned out that the kangaroo rat is not exactly a rat. Here we had a truly terrific concept working: Out in Riverside County, California, the U.S. Fish and Wildlife Service was getting all agitated about the possible endangerment of the kangaroo rat and putting the quietus on a whole range of development projects, just like in the snail darter case. Powerful story line: It is crazy for the government to be standing up for this animal when not 50 miles away folks in Los Angeles would pay plenty to get rid of rats. Undermining our logic here was a passage suddenly stumbled on in the local Press-Enterprise. ''The kangaroo rat is not really a rat,'' explained the reporter, ''but more like a cross between a pocket gopher and a ground squirrel.'' It also came out that some people think it makes a great pet. Maddening, eh? The next fiasco was in the definitional area. Four weeks ago, we had an ''Only in America'' item about some white-looking twins in Boston who claimed to be black (so that affirmative action would get them jobs as firefighters), or at least said they had a black great-grandmother. We gathered that if they could have documented this claim, they would have been $ able to keep their jobs. Next question, obviously: How about a great-great- grandparent? How many ''greats'' can the affirmative-action system live with? If you can get a straight answer out of the equal-opportunity bureaucracy in Boston, you are a better reporter than us. Also planned was a screed deriding liberal jurists who think the American people feel more threatened by insider trading than armed robbery and want this presumed relationship reflected in prison sentences. We came up with this story idea after repeatedly reading that the new federal sentencing guidelines land harder on the insiders than the robbers. But it ain't so. When you go to the sacred text, you find that the guidelines give insider trading a ''base offense level'' of somewhere between eight and 19, depending on how much lucre was involved. (Those numbers are convertible, via a complex formula, into time in prison.) The offense level for armed robbery is in a range from 21 to 27. We shall return to the guidelines in future issues. But they were sure no help for this one.