This also happens a lot with the 550. I've had three of them (two have been replaced under warranty for repeated button failures), and all of them have the glow light "stick" on until I hit another button.
Harmony One - Hitachi 51UWX20B - TiVo Series 3 - CM 4221 - CM 9521A - Onkyo TX-SR601S - Denon DVM-1815 - Panamax Max 4300
