Google Reader isn't updating my RSS feed for hours at a time

I'm using Google Reader to track a lot of RSS feeds, and I have one very important feed that I monitor every day. That feed consists of thousands of items. Lately, I've noticed that Reader will stop pulling in feeds for a few hours, and it is really important that I keep on top of the feed. Is there anything I can do to find out if this is temporary problem with Google Reader? Or, is there any other advice you might have for me? I am thinking I need to switch back to NetNewsWire if I can't be sure Google Reader has me covered. Love any advice you can give me. Thanks!