You can get that if you haven't used it in a long time. GPS systems have a "almanac" which they use to predict where the sats are.
If it hasn't been used in awhile the almanac gets very out of date. The best way is to a reset (known as a cold start on some gps systems). This will mean that your gps will try to download an almanac rather than trying to predict it's position based on an old one.
When the gps is running for awhile it should get a new almanac automatically, hence why it's not a problem if you use it regularly.