PC100 and PC133 Memory

I was purchasing some memory recently for a system that currently has PC100 memory in it. I was going to purchase the PC133 memory as I have typically done in the past when purchasing new memory for a PC100/133 slot. Anyway, the salesman proceeded to tell me that PC133 memory will no longer work with PC100 due to some changes to how PC133 memory is now made. Is there any truth to this or did the salesman lead me down an incorrect path? This was news to me.

Thanks,
Jody Wood

Yes it's a true statement.

Is there information out there somewhere that talks about this? Probably should google for it, but thought I'd ask.

Note:
PC133 Modules are NO LONGER backward compatible with PC100 Machines.

Compatible with 133MHz bus speed system with processor speeds of 1 GHz or greater
http://www.compusa.com/products/prod...493&pfp=BROWSE