Maybe wwwoffle could resist wiping out the cached version when encountering a 404, 500 etc. when fetching a new version.
Silly me, many Debian sites are down today due to a security check. And instead of monitoring getting me sightly updated versions of some pages there, it just blows away my perfectly usable freshest previous copy, in exchange for a framed "Problem Report There was a communication problem." Sniff, if only wwwoffle could do something different when staring a 404, 500 etc. in the face. At least if the code indicates a 'temporary problem condition'. I don't know if wwwoffle has the flexibility to somehow mark which pages didn't get downloaded and why this time, without a separate index or page summarizing oddities encountered last fetch.
