What is it with some of these POIs???

[zztong]

I googled a bit, in English it's called "heisenbug". I'm just more accustomed to the term "floating error" since English is not my native language.

Oh, how interesting. Thanks for sharing.

One of the most interesting bugs I saw was many years ago. Perhaps different, but similar. The bug happened reliably until you turned on debugging and then it went away. It was a timing issue between multiple threads. Some new code had been introduced changing the timing. When debugging was on the threads slowed down enough the timing matched up and it worked. It was rather frustrating to try and... debug.