My Oregon Scientific WR602 frequently loses it's settings and I have to reset it before it will pick up the NOAA again. Once I do that everything is fine for a while, then it loses it's settings again and can't pick up the NOAA in any mode.

It happens, and can be discouraging at times. Not sure what your locale is, but there are certain geographical areas that are more equipped with towers to create a more stronger and consistent signal, whereas there are also areas that have less towers that create a weaker signal. If you are noticing that your WR is frequently losing a signal, or are receiving consistent white noise/static, you might try moving your WR device into a different location. It may take some test time at each location.
Here are some other tips:

1) Make sure your WR is placed in a location away from the use of too many electrical devices. Sometimes, just plugging your device away from your computer, desktop telephone, answering machine, and other electrical devices will frequently solve the problem.

2) Try stationing your device to a higher location. If you have a 3 story home, consider placing it in the upstairs. Same applies with lower levels. If you have a one story home, try stationing your weather radio higher up and test your signal then.

3) Make sure that your WR is capable of receiving a signal. The best signals are typically reached when the receiver is placed near a window with no visible interference blocking the transmission.

4) Make sure your battery is charged or unit is placed in the charging base to receive a solid signal.

5) Make sure your location and channels are set correctly. If you set your location to AUTO, you should have no problem hearing weather reports for your area. If you would like to hear the weather report for your county only, call 1-888-697-7263. Follow the prompts through a simple voice menu.
(OR) go to www.nws.noaa.gov/nwr/indexnw.htm. Click the state for which information is needed.