Why isn't Alt&Title detecting missing alt and title attributes?
When Alt&Title fails to detect missing alt and title attributes, it is likely your markup (code) on the problematic pages is invalid. For example, even a single quote mark in the wrong place can cause Alt&Title to interpret your code incorrectly, and as such, completely ignore missing alt and title attibutes.
Fix your invalid markup, and it is likely Alt&Title will detect the missing alt and title attributes!