help with RAM

I don't know the model number of my Intel board on my 3rd computers, but its an older integrated board with a slot celeron 533mhz processor.. I ran it on 64mb ram but with XP that got kind of slow.. I bought a stick of 128mb ram and added it to the board.. My problem is that the board now only recognizes the 128MB stick, not the total 196mb.. is this normal? The system is faster now as it is, but I would really like both sticks to be recognized, its gonna be hard to sell the 64mb stick for even 10 bucks..

the 128mb is pc-133, the 64mb is pc-100, but that shouldn't be a problem, the board underclocks the ram anyway, its only a 100fsb board..