Help Signal low with Proxim 11a/b/g ComboCard Gold card

I have a thinkpad with a 3com 11mb card. I just got a Proxim 11a/b/g
ComboCard Gold card so I could connect to faster networks. The signal
on this card around my house is about half what the 3com card is. Why
is that? Is it possible the card doesn't like my access point (a
buffalo air station that is a few years old.

Any ideas? I'm certainly not going to get a new access point for this
card if the card itself has such a poor signal. Does the access point
and the card combo make a difference?

thanks
Nancy-
p.s to email take out the nospam in the address above