In my program I've got two data files A and B. The data in A is static and the data in B refers back to the data in A. In order to make sure the data in B is invalidated when A is changed, I keep an identifier for each of the links which is a long byte-string identifying the data. I get this string using BitConverter on some of the important properties.

My problem is that this scheme isn't working. I save the identifiers initially, and with I reload (with the exact same data in A) the identifiers don't match anymore. It seems the bit converter gives different results when I go to save.

The really weird thing about it is, if I place a breakpoint in the save code, I can see the identifier it's writing to the file is fine, and the next load works. If I don't place a breakpoint and say print the identifiers to console instead, they're totally different. It's like when my program is running at full-speed the CPU messes up some instructions.

This isn't the first time something like this happens to me. I've seen it in other projects. What gives? Has anyone every experienced this kind of debugging weirdness? I can't explain how stopping the program and not stopping it can change the output. Also, it's not a hardware problem because this happens on my laptop as well.