The Styles tabs can be misleading since styles are not really "active", they just get applied once when you select them.
If something changes the folder format after a style has been applied then that style is no longer really in effect, but the tab remains selected.
There is probably a folder format associated with E:\My Music which is taking effect when that folder is loaded into the lister. See the Folder Formats FAQ for information on how folder formats are applied when folders are loaded.
It could also be that you just need to re-save the lister defaults using th mode that you want. Set things up how you want them and use Settings -> Set as Default Lister.
There is also a checkbox, Settings -> Preferences / Listers / Options: Update Default Lister automatically when closing a lister which you may wish to turn off if you don't want those settings to change.