It seems that Google Reader automatically deletes items older than about a month, even if they're unread. Or at least it no longer shows them as unread.
It technically makes sense as it calls them "new items" not "unread items". Can I change this behaviour and make it keep showing old unread items as new?
There are some low volume sites like LessWrong with long, complex, and not urgent articles which I don't read quickly after publication, but only occasionally given free time, and it's hard to use Google Reader to track them.
Alternatively is there any way to fool Google Reader into thinking such items are more recent than they are, perhaps by some Yahoo Pipes tricks?