Many markets can be very frustrating for sellers right now. There are 4 things that affect whether or not a house will sell. These are location, which can't be changed, price, condition, and marketing.
Most markets in the country right now are buyer's markets. This means that price and condition are critical, and your agent needs to be marketing your home through a number of avenues.
Look at your home through the eyes of a buyer. Is it neutral enough so they can picture themselves living there, yet warm and comfortable enough that they would want to spend time? Is your home staged? Do you have all the personal photos off the walls? Are your rooms set up for a specific purpose? (ie: a bedroom should not have an office, a TV, a chair, and a bed). Are the paint, flooring, kitchen, bathrooms updated?
If your home is in the best condition and you are still not receiving offers, look at the marketing your agent is doing. Is your home on the internet with a number of photos and good descriptions? Can you find it on Realtor.com, Trullia, Zillow, Yahoo homes, etc? Is it being marketed to other agents in your area who are working with buyers?
If your answer to all the above questions is yes, then your price is too high for the market you are in. If your agent says the price is correct, then they either don't know the market or they haven't counted for the recent market shifts. If you aren't happy with what your current agent is doing, you can always list your home with someone else. You can ask for referrals, or contact other real estate agents and ask them for a good Realtor in your market.
The frustrating thing is that there are fewer buyers in this market. Lending guidelines have become stricter, people can't sell their home to buy another, and fewer people are in a monetary position to purchase homes. It becomes the law of supply and demand. If the supply is high and the demand low, then you need to reduce your price.
You have 2 options...you can either reduce the price, or wait it out. The downside of waiting it out is the longer a home is on the market, the lower the sales price.