Do you mean 40 to 80kbps? 800kbps is a huge datarate. I was able to run a 155 kbps datarate, 688x288 XVID successfully, created with FairUseWizard. Mplayer did however choke on a 188kbps datarate, 704x368 XVID. The 155kbps movie file worked out to be about 900Mb, the 188kbps was more like 1.3Gb. Both files play fine on an Archos 604 and 605 (which also runs a version of open source Linux) so one would think, with proper tweaking, they should run fine on the n800 (unless the Archos has some sort of hardware decoding in it's video chipset.)