Just in case you haven't tried it yet, Summize.com just saved you tons of time and frustration for when Twitter Replies stresses out. Summize somehow tracks all of the tweets from Twitter, and is a big search bank for words that you need to know have been mentioned.
If you aren't in the habit of clicking that Replies tab in your Twitter profile, you should start. It's a great way to know if someone tweeted back to you, or randomly to you. You can't be on Twitter all day long, so if you tweeted in the morning, and then are checking in at night, you can see if anyone responded to you, or randomly tweeted you, by going to Summize.com and entering in your Twitter name into the search tab.
Or, if you are checking on what's being said about your company, your competition, or a product you're wondering about, just put it in quotations (if it's longer than one word) to get an exact match from Summize.com. Just like you would do an exact match search in Google.