I am using Debian Lenny with 2.6.30 kernel on my Intel Atom Poulsbo chipset computer and I get the following messages in my dmesg when I start the X server:
[ 22.760737] mtrr: type mismatch for 3ffc0000,10000 old: write-back new: write-combining
[ 22.760805] mtrr: type mismatch for 3ff80000,40000 old: write-back new: write-combining