Well for the first year i had them they were all happy and fine, never had problems... then one day, one of them discovered they could actually catch and eat them... then thats when it was all over...
But from what i've heard from other keepers, normally it should be okay and that you can mix cherry red shrimp with dwarf puffers... but to be on the safe side, i would advise starting off with maybe 2 or 3 shrimp just to see how they fair against the puffers personality...