I'm sorry to say it, but just found that the new automatic mirror lock enabling/disabling feature is provoking problems especially with Digic 4 cameras
(500D and 550D for sure)
While the new version 1.10 is done, a fix for the unregistered version can be found here.
http://www.ideiki.com/astro/Beta.zip
All registered users can contact me at any time and will send them the fix for the registered version.
A lot of apologies for the inconvenience!!!