lizzard394,
DIMM slot 1 is not necessarily the closest to the processor.
On Asus A7V133 motherboard DIMM slot 1 is the farthest away from the processor.
Also, PC-133 SDRAM is usually backward compatible with PC-100 SDRAM.
PC-100 SDRAM will not work with a 133MHz Front Side Bus unless the BIOS allows you to set the DRAM frequency independently.
england,
Check your motherboard manual to be sure you have the memory configured properly.
Hope this helps. Good luck.
John