From what I am able to determine, all the computers involved are set to English.

And yes, I've seen puzzling problems when dealing with Asian-language configurations. We ran into a problem where our application would abort with syntax errors whenever run on a computer set to Chinese language (I also verified that the same problem would occur in Japanese-language configurations as well). The problem had me and my co-workers scratching our heads -- until I spotted some string literals that contained upper-ASCII characters and realized what was happening. It didn't take long to patch the code (recode avoid having string literals containaing characters outside of the ASCII range 32-126) -- though it took a bit more time to explain to my co-workers as they weren't familiar with double-byte characters or non-ASCII character encodings (noticed that nowadays you get puzzled looks from folks when you mention EBCDIC).