Working in my test blog (not live to the web), I'm having some issues with the digest feature.
WordPress is successfully pulling in the daily tweets, but the blog post always stays unpublished and throws the error "Missed Schedule"
*occasionally* There seems to be a problem with multiple copies of the Twitter post being populated, but I haven't been able to recreate that consistently.
Also (different problem) I've noticed an intermittent issue with changing the time for Twitter Tools to pull in tweets. Honestly, though, once I can get things working the way I'd like and on the schedule I want, this would cease to be an issue...