It sounds like it's just a javascript/browser limitation. You're trying to plot way too many points on the map. Even if you're only trying to show 4 or 5 regions, each long/lat point that it takes to plot that region increases the load on javascript and the map. This is why when there's a need for a large amount of points, you probably need to start looking at a server side mapping solution.
On the other hand, if all you're wanting to do is outline some countries, you could switch to using the svgReader extension. If you want to also plot points, you could maybe find a less precise set of boundary data. If it's using that many points to outline a region, it's probably being too exact in its drawing of boundaries.
