This has been a thorn in my side for quite some time. Love, love Pandora. However, there should be a way to lock a station into a genre of music. What I see now is if you use the thumbs up or down the station starts to evolve and play music from the other stations that I've liked. So basically its corrupted. The stations I ignore after picking the artist/song stay true for staying towards that style. Please fix. This has been going on for years....