On Timely's site, the only "standard" version for download is 1.9.4.
This is the version I installed on a client's site.
On my other sites, I have an invitation to upgrade to 1.9.4. I'm not using the pro version, and certainly won't upgrade to 1.9.4 standard until I'm confident it won't mess up my other sites.
I have posted the other problems in this forum: over-expanding agenda view, event times flipping around in a random way when saving posts... I tried the plugin with the default theme and nothing changed. In addition, the theme has nothing to do with the event times changing when updating a post.
There are no plugin conflicts, I checked that too.
When I uninstalled the plugin I got a 500 error and my whole site was down; had to bak. the htaccess file to get it up again.
I'm mostly concerned that so many people have tagged this version as "broken" with WP 3.5.1 It does indeed seem to be the case... I love the plugin and would like to upgrade, but I'm terrified to do so right now.