A Code Glitch May Have Caused Errors in More Than a Hundred Published Studies
I've implemented algorithms I dug out of original research papers, which often included sample code.  (That's why I first learned to read Fortran!)  I've almost never gotten results that match the authors' exactly.  Sometimes the bugs are obvious, and sometimes they're subtle.  I'd estimate that 100% of sample implementations in published research papers have bugs.  Researchers, even in computer science, are usually not skilled programmers.  The product for them is the paper, not a program.<p>It's the same category of problem as "enterprise software".  Whenever the <i>customer</i> is not the <i>user</i>, the user gets screwed.  With research, the customer is the journal.