size useravatar & size thumbnails userlist

Hola:
My users choose your avatar from the gallery.
The Gallery is personalized with images of different sizes.
Want to keep these different sizes to display in profile.
Well. Perfect. I like it.
Now comes the problem:
In user list thumbnails being displayed are sized as a gallery. Large, small...
As I can do to show user list images at the same size?
Tanks

Hola:
Mis usuarios escogen su avatar de la Galeria.
La galeria es personalizada con imagenes de diferentes tamaños.
Quiero conservar esos diferentes tamaños para mostrar en perfil.
Bien. Perfecto. Me gusta.
Ahora viene el problema:
En user list las miniaturas mostradas son de tamaño como galeria. Grandes , pequeñas ...
Como puedo hacer para que user list muestre todas las imagenes al mismo tamaño ?

Gallery images don't have thumbnail sizes. It's 1 size everywhere. You'll need to supply them at acceptable sizes for multiple locations or try to use CSS to downscale them.