I’ve also found that compiling large packages in GCC or similar tends to surface problems with the system’s RAM. Which probably means most typical software is resilient to a bit-flip; makes you wonder how many typos in actual documents might have been caused by bad R@M.

That's exactly how my bad RAM manifested itself. In fact, I was compiling Firefox, and gcc would get a segmentation fault at some random point during compilation. I'd have to clobber and restart the hour-long build. It was only when gcc started crashing while compiling other things that I even started considering the possibility of hardware failure. I'm a software developer, and based on what I produce myself, I just assume that all software is horribly buggy. ;-)