My best development PC has been plagued by rare data corruption problems that occur most often when updating or handling large files. They were so rare (half a dozen times a year) that I lived with them - until some substantial overnight file processing started hitting issues almost every time I tried it.
Examination of the files showed very infrequent but catastrophic 1 bit errors (for example an 'L' turning to an 'M' in an ascii file).
I often print out a sheet with the module positions on it when I am working on a site but if the printout is not handy I type in the url with index.php?tp=2 at the end to display the module positions.