Upon testing it became apparent that the DiscussionsGrid plugin and the Date Separator plugin don't display well together.
Please describe the problem more specific. Do you want to prevent that a someone using one of both plugins gets into trouble or do you want to have a solution that combines both features?
When both plugins are activated and the DiscussionsGrid is displaying a grid the date separators are showing separately outside the grid and break the tabular view.
My digging shows it is an artifact of the fact that the date separators are created via the "between discussions" hook outside the "div"s of each displayed discussion.
I'd like to alleviate the issue. Perhaps @phreak can chime in, or perhaps you can figure out how my plugin can support the date separators plugin. In the absence of a good solution I may include some separators functionality in DiscussionsGrid if enough people would download it...
Either it can be solve with CSS or you need additional HTML markup. If it could be CSS, I personally would simply add this CSS to the readme so that anyone could apply it on its own. If it requires additional HTML markup, it might be easier/wiser to implement such a feature completely in your plugin
The way I see it each plugin emits content in it's own div so that information is separated and stylized differently. Important point is that my plugin's div encapsulates the entire discussion so other plugins that emit content within the discussion usually don't conflict (e.g. Discussion Note works fine). Date separators emits outside of the discussion (between them) and is unaware of the workings of the grid state. It's all evident with browser inspector.
Perhaps phreak who last updated the Date Separators plugin will have an idea.
Thanks for pointing this out. I am looking into an update ASAP and keep you informed.