It really shouldn't make a difference. I've never had to change whatever Windows detected... no matter what I've added. It seems very odd to me that changing that one thing would make a difference in how much RAM is there.
<font color=red> If you design software that is fool-proof, only a fool will want to use it. </font color=red>
It wasn't the amount of ram, but rather the manufacturer. I had CorsairXMS 3200DDR ram and went to OCZ Platinum Series 3200DDR RAM, and the OCZ just had an incompatibility with the ACPI settings in my computer... so I am still baffled. The reason I do not think the amount was the difference because I installed the OCZ 1 stick at a time and it still repeated the problems. No forum seem to know the difference between these settings.