Theme hook is not in the correct place.

Adv CSS/JS Agg - Theme Hook - Theme hook is not in the correct place. I cleared the cache as requested. Here is Hook Theme Info Debug:

template_preprocess
template_preprocess_page
context_preprocess_page
authcache_preprocess
authcache_preprocess_page
skinr_ui_preprocess
contextual_preprocess
context_layouts_preprocess_page
dynamic_background_preprocess_page
follow_preprocess_page
smart_helper_preprocess_page
lightbox2_preprocess_page
mobile_codes_preprocess_page
skinr_preprocess
advanced_forum_preprocess_page
seven_preprocess_page
ctools_preprocess_page

Module seems to be working (with JSMin and CSSTidy modules enabled even), but I don't know where to start trying to solve this one on the Status Report page.