No FreeRide, I had one stick of 256MB Corsair PC2100, and it read it as 256MB. But I just installed another 256MB of Crucial PC2100 to my machine and it is reading 511MB, not 512MB? I'm not sure what could be going on in your case, but if it were me, I would pull it out and put it back in just case your machine did'nt read it the first time.(?)
Good luck! Bob535