You should learn how to edit templates in XOOPS.

- copy template set from default to new name in template manager
- set default template set as the new template set in preferences
- edit myalbum_*.html in the new template set in template manager
(don't edit original template file)

And the template you have to edit is myalbum_categories.html only.
You need not to edit myalbum0_categories.html etc.