Starting out; strange issues (single-line comments)

[eluser]pointfive[/eluser]
[quote author="PhilTem" date="1349124270"]Or you have some strange white spaces in your file?[/quote]
This looks like it was the problem. It seems I was working with a copy of a file which uses "line feed" instead of "carriage return". It doesn't like single-line comments with line feed for some reason. Weird.

Anyway, thanks for the help!