Guilty as charged...kind of.... I've fallen into this trap a couple of times.... assuming that the same symptoms are the same problem as last time. However I do keep an open mind and usually get onto the right track fairly quickly. Rule No. 1....NEVER assume......
Have any of you suffered from the theorist who learns that a certain problem causes a certain symptom and is then incapable of understanding that the appearance of that symptom does not necessarily indicate an occurrence of the same problem? I don't have an illustration to hand but trying to explain the fallacy can drive you close to madness.
Some of my coworkers will recognize these. A cursor controlled from remote location while the user's mouse still has some control over the cursor. This was good for a couple of laughs. The other one was to magnetize the users CRT while the user was not around. The user ran a lava lamp type screen saver and tried to come up with explanation for why CRT would become magnetized. The user would degauss the CRT to fix problem but the next day the problem would reoccur because one of his coworkers would re-magnetize the CRT before he got to work. One day the user was shown the magnet that was used to make the mysterious event occur thereby ending any of the possible complicated reasons for the problem. This is a lot like magic that uses a shill, it works very well. We often make assumptions based on what we think is normal. These are both cases where Occam's razor works well to try and understand the problem.
Great story John...I wonder whether there are any collection of engineering stories published somewhere...perhaps having a book that covers them would make engineering more interesting to a public at large...Kris