Melinda,
I can't say as for why the servers seem to act up, only to say that as VATUSA, we have no control over any of the servers, or any way of ensuring they don't hiccup during the busy events. The servers are operated entirely by VATSIM.
I will say this though, the server splits, in my opinion, have gone down dramatically compared to even a year ago (although it may not seem like it). Unfourtauntly, there isn't much we can do, other then to connect to another server once disconnected.
I do understand your frustration though!
-Mike