Remove both toe straps and screw the SL toe straps onto your Altlas binsings. Try it then, that way you'll know for sure what the problem is.
It sounds like it might just be the material like Extremo said, but you can check by doing this.
If the new Atlas toe straps you sent for don't solve the problem, just put the SL straps on whichever bindings you plan on using for a day.
If the thread lock wears off the off the screws from doing this often you can always get some more really cheap from a hardware store. I personally use thread tape because it's easer to remove when old and easier to reapply.