I've thought that a crippled fish leaves only a small wake with occassional little skips and hops, which is how I sometimes retrieve my popper. I experimented with the slider reversed (normal) but found that I caught just as many fish and, most importantly, it made casting a lot easier. Aesthetically, to me, it also looks more like a fish with the pointed end forward.
To Philster's point, I have also found that even in windswept waters, my small #6 poppers leave enough "nervous water" in it's wake for me to see. If you lose sight of your popper, give it a big, healthy pop to identifiy itself for you.