I'm buying a 128mb stick from Mushkin but I cant decide between PC100 + PC133. I'm running 2 64mb PC100 (8ns) sticks right now at 133. I've heard problems where the new stick isnt recognized when mixing different speeds. I just need the new stick to run at 133 without any problems. I've narrowed it down to these choices:

Athy tested PC133 - $168
Infineon PC133 - $129
Mushkin PC100 - $119
Samsung GH PC100 - $189

What would be the best to go with? 222 @ 133 would be nice for the future but I'm running 333 with the PC100 so I'm more concerned with compatability.