There's a problem with phones running Ice Cream Sandwich and the Market version of Llama, which is caused by Llama trying to access calendar events. This is because the Calendar API in Android was never officially released, so had to be implemented using unofficial API calls. Now in Ice Cream Sandwich Google have finalised a way of reading calendar events. Unfortunately, it's subtley different to how Android 2.3 worked, so Llama craps itself.
There's a test version that ignores the problem rather than crashing on the blog, but Calendar events aren't working just yet. I'm working on it :)
As usual, backup your data before installing the test version, just in case you have to uninstall and go back to the market version.
As an annoying note... Android give developers an emulator to test this kind of stuff. However, they don't let the emulator log into a Google Account, so you can't access a calendar! D'oh! If you'd like to lend a hand, get in touch by pressing the Llama-question-mark button in the app and emailing me. Ta!