After many months of Alfred usage on this machine I've started to experience this in the last few days. A restart didn't help. I tried to capture the requested info in Activity Monitor but it's not a long enough delay to get there, click the cog, and start the sampling It is long enough to be quite frustrating though I"m going to try clearing the cache and rebuilding the OS X Metadata including deleting the spotlight file and I'll report back the result.
(OS X 10.9.4, Alfred 2.3 (264))