You probably have a startup process consuming a lot of CPU - I've replied with more details to your other post.

Do you have more details - could be a weak signal or flakey access point? My WiFi is rock solid (Linksys WRT54GS v2 w/Sveasoft firmware). I don't use WiFi out and about though so my N800 doesn't get to associate with many other access points. The only random wifi drops I've experienced are with a K-Corp access point at my parents - this is due to rubbish firmware on the K-Corp which causes it to reboot periodically and thus drop the WiFi... note to self: replace K-Corp router on next visit.