Corsair XMS 2400 with CL=2 performs like CL=2.5

[klpickrell]

I have XMS 2400. When I run the Sisoft Sandra memory benchmark in Windows 98, it scores about even with DDR2100 CL=2.5. Is this right? The bus speed is still 133mhz and the CAS timing is set to 2 in the bios. Is this score accurate? Does the Corsair memory really run at CL=2 or will CL=2.5 memory work when the timing is set to 2 and the motherboard just adjusts the clock automatically? What's the deal?