Mixed mode (b/g) not working - only "B-only"

My Access Point is a Linksys Broadcom-based WRT54GS running dd-wrt v24. I've tried every variation of settings, and everything works fine if the network type is "B-Only", and the rabbit will never connect if the network is "Mixed". I have several PC's that work fine in both G-Only, Mixed and B-Only mode.

Anyone else have this problem?