Evan i have fixed this but im no coder, im not bad with CSS but php im really not so good at but given time i can work things out and find a way round but i now know this is not a plugin issue and technically not a theme issue either, ive come to conclusion this is a bit of bad work on WP core in how it handles the default sidebar
by default WP does not give admin option to switch off default sidebar but if it did nobody would have broken themes a lot of the time when they try new plugins.
this is the culprit code
<div id=”sidebar” role=”complementary”>
this is the left sidebar
if a dev makes a theme whereby you simply add your own widget and that itself replaces the sidebar with a theme sidebar then some ( quite a lot) of plugins will display incorrect when showing a single view which is exactly what what happening with your plugin on my site so in single view which is controlled by single-timeline.express.announcment.php file is laid out to pull in default WP view rather than the themes view so it will pull the default sidebar back creating a conflict in theme and ruining the layout
in my case it was the default sidebar then placing itself underneath the content of the announcement.
you may know more than me as a coder to make good solution because as said im not a coder so i have had to copy code from my theme template that would cancel the default sidebar and place the theme sidebars but this means ive hardcoded your plugin file so i could never update unless i do this again after an update. im not sure of any other way to get round this though, theme dev would have just as much problems because they cant code to suit every plugin out there.
why oh why dont WP just add a button in admin to switch off default sidebar and save thousands of users this headache ?
Keep up the good work Even, its improving all the time