Classic Theme: thumbnails shown for sub-album in gallery v2.3 (fixed)

I have modified the theme.inc and album.tpl according to the instruction in the following link so that the thumbnails are shown for sub-album in gallery version 2.2.x.

http://codex.gallery2.org/Gallery2:How_to_use_Thumbnails_for_the_Sub_Album_List

However, after I upgraded to gallery v2.3, the code doesn't work and the thumbnails are not shown anymore.

I would like to know if anybody can help me with this?

Thanks!

I've fixed it by modifing the theme.inc file again. Thanks!