Jim, If it's a major problem, you could get THIS
or if it's a minor problem you could make up a small skid wheel for your receiver hitch.
Update: I see my link won't work because of the IRV2 filters. The guy makes a major league receiver hitch wheel and his company name is dumb but it's a neat product. You can get to it by typing www.h*ll-ya.com
in your address slot. Replace the * with an e -