Is anyone else having trouble with their client occasionally stalling out...?

I woke up today to find my miner had been hashing away on the same block for more than 4 hours because one of my clients had stalled and was pretty far behind in the actual block count even though the client said it was synced.

What's really weird is that my other client (I have two pc's and one runs cgminer on load balance between the two clients) was still perfectly synced but the miner was not receiving new block notifications from the synced client either.

Anyone else experiencing anything similar...?