Hello,
I live in USA and I bought the babybit DVDs a few months ago. I have had no problem with the format because my DVD is able to play both formats (PAL and NTSC).
Before buy them  I was making some inquiries and it seems that nowadays many DVD players and televisions you can found  on the market are able to display both PAL and NTSC.
Even I tried it on my PC and it worked fine!.
 
I'm happy with the results. I bought volumes 1 and 2 and my son have liked it.
In a few weeks I'll buy volumes 3 and 4.