battery light problem

[turbostar]

My 2006 Silverado 1500 has a problem with the battery light that is getting worse. On startup(sometimes) the battery light stays on. At first it would happen once a month or so but it is happening much more frequent now. When it happens the gage shows it is charging normal but the battery light is on. If I turn off the engine and restart, then the light goes out. Very confusing as the system is charging normal when the light comes on. Any ideas or experience similar? TIA