Came across another gem of an article by Joel Spolsky. It's a pretty old article written in June of 2004, has lot of tidbits and I really enjoyed reading it, so much in fact that I read it twice! So hit the link below and give it a read if you haven't already,

How Microsoft Lost the API War - Joel Spolsky

excerpt,
"I first heard about this from one of the developers of the hit game SimCity, who told me that there was a critical bug in his application: it used memory right after freeing it, a major no-no that happened to work OK on DOS but would not work under Windows where memory that is freed is likely to be snatched up by another running application right away. The testers on the Windows team were going through various popular applications, testing them to make sure they worked OK, but SimCity kept crashing. They reported this to the Windows developers, who disassembled SimCity, stepped through it in a debugger, found the bug, and added special code that checked if SimCity was running, and if it did, ran the memory allocator in a special mode in which you could still use memory after freeing it."