I was able to see the same behavior by renaming a band in ArcCatalog 9.3.1 and then viewing in ArcCatalog 10. It goes back to the original band name. I also noticed the renaming a band in 10 remains the same in 9.3.1. I wonder if it has something to do with how each version is reading the file. If you do not get any other responses, I would suggest that you contact Esri Support so that this issue can be looked into further.