Using expiry selectors with $cache

[MarkE]

I am attempting to use an expiry for a cache item that is triggered by page updates matching the selected pages.

Doing $cache->getInfo() shows that the cache item has been created correctly:

[311] => Array ( [name] => dueNoticeBkg459 [type] => array (2 items) [expires] => when selector matches modified page [selector] => (template=Settings|BusinessProcess|BookingStatus), (template=Booking, title=Bkg459), include=hidden [size] => 271 )

I've tested the selector in the "selector test" module and it lists the correct pages. However, if I change and save one of those pages, the cache item has not expired. It works with a simpler selector such as 

"template=Settings, include=hidden"

but not with the "or group". Are "or groups" not allowed in this context, or am I doing something wrong?

[MarkE]

Just found this small print on the selectors help page:

Please note: OR-groups work with database-driven find operations, but not with in-memory filtering (where they are less useful).