Litecoin difficulty rose 30% this morning, so that could be somewhat related to the pool's drop in share rate.

Is your mining software claiming shares which are then rejected, or is it just not finding any shares?

I've noticed my mining fluctuates between finding a lot of shares, and finding no shares, at the moment, and the pool's website is often inaccessible (though the RPC requests seem to get through, on different addresses).  I wondered whether it's DOS-related.