I downloaded DoodleToDo on my macbook air running 10.7.4 and it won't sync. I've tried the 0.9.9 and the 0.9.10 (latest) version both with the same behavior. I know it's not problem of my credentials (username and password) since I have two Toodledo accounts and I can reproduce this problem in both 0.9.9 and 0.9.10 for both accounts which I can successfully login to from Toodledo.com.
P.S. Already download the dashboard widget which is cool, but I want something I can use offline too.