Recently, we completed a Windows Application and started running it. This is application was written using Framework 3.5. Strange thing is it runs on several machines but not on two of them - we tried on 8 machines total. Of this 5 of them were identical in every way - Windows, patches etc. Whenever, we run this, it will crash - but only the portion that enables multi threading.
This reminds me of a similar problem I had several years back when I tried using Harvard Graphics on a Acer desktop where the graphics was really bad but not on other machines.
Another incident I experienced more than 15 years ago when we were using MS DOS. I wrote a Clipper program for my office. It copied into two identical machines. Again, it ran on one but not on the other.
I guess I was lucky to encounter all these. We can't blame the programming or the programmer. I wonder whether there are some minor bugs in the processor. Hmmm! This is probably the worst thing that can happen to a programmer. You write your program and tested everything but it does not work on the machine it was meant for.