Nothing particularly odd there. Personally I'd do the @ with the subscribe call.
What you describe has happened to me in situations where callbacks are involved in rendering.
The important thing for reagent to work is that the line-chart call is invoked and before it returns all r/atom's it should watch are dereferenced.
Small nit... the clj->js is probably not needed because you're using [:>
which does clj->js for you.
yeah i realized this last night when i was looking into reagent. Thank you. I actually made it work. i removed timestamps/date from x and just use indexes now and it works. It is rendered properly. What i think happened is that lib wont rerender until enough time has passed for it to make redraw make sense. i will dig bit into this and report my findings