Hello.
We had internet before, and it did this as well, with a completely different provider and type of internet, before it was with a company called Cox. And it was cable.
Now we have cricket wireless, and its doing it still so I don't think it's the provider or the cable.
When I start to load a page, it will SEEM to get stuck and not respond, until I move the mouse, and then it pops up right away.
That's about the only way I can explain it.