How many shares did you submit, and how many were accepted?

suprnova.cc as a whole has had a hard time finding blocks for the past few days (down to about 20% of the block rate it used to get), and this will translate to reduced returns for the miners.  However, it looks like this was just bad luck - the share rate is normal, there's no indication that the pool's overall hash rate has dropped or anything like that.  There were recent DOS attacks, but these seemed to mostly affect the web site front end, not the pool servers.  Still, I have seen a lot of failed RPC requests, which means your miners have to sit idle while the RPC retries, and that will take its toll.

I'm not sure where you got your 4.5 LTC/day prediction from - it sounds a little high, I'd say if you're truly achieving 800 kH/s then you should expect around 4 LTC/day at the current difficulty level (205ish).

I would give it more time though, and see if the pool's block hit rate improves, and especially pay attention to your shares and whether they're being accepted.