q/.../ is identical to '...', or a single-quoted string. See perlop.

Perhaps you were using double-quotes, and something in your string got interpolated, breaking it? That's why I kept trying to get you to test your assumptions, specifically: that these variables held the values you were expecting. That's why my examples had no variables at all, and I kept saying that if your example was any more complex than that (included variables, for example), then that additional complexity was almost certainly to blame. If I'm understanding all of this, it was.