Are the dark marks raised or do they look more like scratches on the tile? If the latter, they could be metal marks (e.g. from a metal level or bar used to level the tiles themselves; our guys constantly checked and re-checked the tiles for level). They could also be pencil marks. Our guys sometimes marked tiles that needed to be cut.

If this is the case, depending on your tile (if glazed porcelain, s/b ok), try a little powdered Zud on a damp sponge, and rub the marks with it. If metal marks (or pencil), they should come off. I use Zud to remove knife marks on my dishes (or spoon marks inside white mugs--though I usually let those get really bad before thinking to do it!).

JSS-- any chance you could take a couple of pics and post them?

Yep- will do tonight. Thanks!

This is my first attempt at pics in a post. This photo is huge so I am not going to include the others. I noticed that if you click on the photo tho' it will link you to photobucket and you can see the rest. I should add that these marks are really not noticeable standing in the bathroom, but I have had to do some buffing, etc and on my hands and knees I noticed them. This probably seems super nit-picky, but I have already cleaned the more noticeable stains/smudges across the tile face... with a 50/50 vinegar water solution (is that BAD?). I am afraid to get any closer to the grout though which is why the smudging you still see is near the edges. I can live with it, but if there are any suggestions for cleaning up a bit more I would be grateful! (I should add that there are only some places like this throughout the floor, most of the grout lines are "tighter" and cleaner, which is probably why these stood out to me in the first place) Thanks!

Okay. That's no big deal. Get yourself a NON-acid grout haze remover. it'll take care of those little wisps coming off the grout joints. I was worried that you might have minute clefts in the tile that had coaught grout, in which case this wouldn't work. But this is just a matter of cleaning the grout job. No big deal. You can get it at either of the big box stores in the tile aisle.

So it IS haze! Thanks Bill, you're the best.

Thanks! I liked it enough to pick it- and am liking it more and more. JSS