Contexts
 

some tasks I assign a context to show up in that context view, others don't. Anyone else having the same issue?

What can you say about the ones that are assigned a context but don't show up in context view? Do they have start dates, due dates. Are they in sequential projects and are there other tasks ahead of them? What are your filter setting?

In all likelihood it is because you are only viewing "Available" or "Remaining" actions and those that aren't showing up don't fall into the view category you have selected. Click the [B]View[/B] button in the toolbar (or press command-shift-v to toggle its display) and check your filter settings - e.g. do they all show up again if you select [B]Any status[/B]?