I have uploaded a new snapshot of Deadwood today. In this snapshot, I have fixed a bug where the size of the cache when loading the cache from a file was always determined by looking at the cache file. Now, Deadwood will always look at the dwood2rc (configuration file) to determine how many entries we will allow the cache to have.
If you shrink the cache size in one's dwood2rc so all the elements in the cache file no longer fit, Deadwood will do the right thing and discard "less important" cache elements. This is because Deadwood's cache starts off with less important elements and finishes with the most important elements; when reading the file, should the cache fill up, Deadwood will simply discard the less important entries as it loads more important entries.
It can be downloaded at maradns.org/deadwood.