It wasn't the "back burner" that helped or not researching for a while. When I came back to the problem I was doing something different. If you are about to give up, maybe some of these ideas will help.
1. Don't just look at the problem as a person with dates and places. Look at everything about the person and his or her associates and relatives. Go back through all of your notes and sources. Reread them thoroughly and see if anything "pops" out as something you may have missed in the past.
2. Write out the problem. Putting pencil or pen to the problem often helps. Sometimes I print out a family group sheet and pencil in my comments or ideas. It helps to see something in print, even more so than on the computer.
3. What has changed? The genealogy world today is changing by the day. New records are being found and new digitals and transcriptions are being placed on Internet. When was the last time you checked Internet web pages such as the USGenWeb, mailing lists, message boards, archives and databases? With your problem in mind, use search engines, such as Google, to see if anything new is on the web pertaining to your family, surname or locations. New genealogy sites are being added daily!
4. Did your ancestor live in a vacuum? They were influenced by what was going on around them, not just by their own family and relatives, but the economy, society and political environment in which they lived. To better understand your ancestors and why you are not finding information on them, do some serious studying of history. You might discover that they moved because of an economic depression. The Great Depression was not the only one that occurred in the United States.
5. Do you really know where your ancestor lived? Research is easier if you look at maps and study county formations. The physical structure of the land was influential in where people lived and the land they purchased.
6, Internet is wonderful, but it also isolates us from the real world of genealogy. Rub elbows and dialogue with other genealogists, join a genealogical society, fit it into your monthly schedule and you will reap great benefits. Visiting with other genealogists about your research problem may open new channels for your research. It is also great fun to attend genealogical conferences. These can be local, state or some of the big ones which are held nationally.
7. Are you researching "hit and miss?" It helps to be consistent with your research methods. Keep a log of your research habits. What is working and what is not working? Allocate quality time for your research.
My advise is not to give up. You don't need to put your research on the back burner. Start over with a fresh approach, apply some new research ideas, such as outlined above, and see what happens. Sometimes a clear, focused mind will do wonders!