I guess asking for new straps cannot hurt. But FWIW the 11/12 390 toe straps work perfectly with my Vans boots - in fact they are just as good as the Burton ones in my experience. The Rome straps look flat but they actually stretch and conform to the boot really well.
Good to hear that yours are fine. Exactly what Vans boots do you have?
The toe sections on most boots are pretty solid and don't have the potential for problems like reneftw has with his boots.
It would be cheaper to go with new toe straps, but if new boots are an an open option than that might be the best thing to do, as there wouldn't be this problem to worry about with the current bindings or any future bindings.
I'd say get new boots as a last resort if new toe straps still don't do it for the Vans. Hopefully they will though.