I’ve fixed a few bugs with the new log viewer. The fixes should be in the next binary (Nov 29 or later).
Because one of the bugs involved searching, you’re going to need to reset your Adium log searching indexes. To reset the search index, quit Adium and:
Delete the ‘Adium’ folder from at ~/Library/Caches (From inside your home folder).
Next time you open Adium’s log viewer it will rebuild the index, and all should work 🙂