Figured this out.
There seems to be a four letter minimum word length on the wiki search terms ... so:
asus eee box
only gets searches for:
asus
However, searching for:
asus b202
works fine!
So it's not a fault. The page is just buried in the results. Probably to do with the mysql ft_min_word_len variable for fulltext searches.
Anyone else think it's worth changing to three letters? It might help folks find valuable info ... but then again, would it create a big performance hit?