Hello
With sh404SEF enabled, album's URL look like (in the case of a user album, but issue is also true for group or event albums):
community/albums/user/88-username/albumname (where 88 is the id of the user)
It should rather be:
community/albums/user/88-username/99-albumname (where 99 is the id of the album)
in case 2 albums have the same name.
Thanks