I'm also getting the same error when trying to access the internet.
"internal error Application "Web" closed "

I'm using the N800 . I've only had the unit for two days and tried to load a Maemo application from maemo.org

I noticed I was constantly getting the missing file "libxau0" message so I tried searching for this file to install... but couldn't find it ?? Since then I've read in a few posts that "libxau0 is an old file that was used with the ver.2 (2006 os) and is really not required for the 2007 OS but get this .. alot of the older software applications created stilll need it.... Any way to cut a long story short while I was at Maemo.org I insalled the Maemo Mapper. Now I can't access the net any more ?? I also flicked over to using the "Red Pill" (have changed that back to blue now)
the red pill allows more detailed user settings etc... (a bit like hacking a pc game with a secret password that unlocks hidden realms ....

Even after I removed Maemo Mapper ( I don;t think Mapper was creating any conflict in the first place) but something has gone wrong now I'm guessing that maybe by updating to the latest OS (the one with skype) this might fix my problem.. I'm going in to university later today and will try using a PC there to load up the new OS.. right now I'm on a mac... I read here in the forum about flashing the N800 bt I want to exhaust other options before flashing.. sounds abit scarey...