The OP is specifically talking about singletons.
No (s)he isn't. Flopid just talks about having static/shared (i.e. global) variables in the original post, but there is nothing that sounds at all like a singleton.
@Flopid: I'm not sure how you were using the static keyword, but it has different effects depending on where you use it. I wrote a little post on my blog about it which might explain things for you a bit. It's hard to give you a more specific response, seeing as I'm not sure how you were using static, but this might clear some things up. It's possible you were making a static global variable, which would indeed mean that each source file gets its own copy of this global variable, and changes made from one file are not reflected in others.