should cache previous page to avoid redrawing

[jidanni@xxxxxxxxxxx]

I'm reading a big page like
http://en.wikipedia.org/wiki/Vietnamese_language offline with
WWWOFFLE. I register links to be retrieved later using RET
(w3m-view-this-url), after which I hit B (w3m-view-previous-page). I
do this for about 20 links. Each time upon B, I get
Rendering...done
Fontifying...done
I.e., the page has to be redrawn all over again.
Can't the previous page be somehow cached as it is very likely the
user will go back. Even more likely that visiting another concurrently
running session window, for me at least.