no dma on ibook with kernel 2.6.30-gentoo-r4

i have 2 ibook g4 here.  the older is 1 Ghz, powerbook6,5 and the newer 
one is 1.333Ghz, powerbook6,7.  i updated to kernel 2.6.30-gentoo-r4 on 
both and dma does not work on the older but works on the newer.  used a 
default `make pmac32_defconfig`   i even compared output of `lspci -k` and 
the same modules are loaded for 2.6.27-gentoo-r7.

does anyone have dma working on an older model ibook ?

should i be using the newer scsi emulation ?  i looked but didnt see the 
drivers.

thanks

matt