10 October 2007 at 1:43pm
yes, this is indeed a bug, exactly here:
we've been using some light php-based caching of relations for a while, and forgot to invalidate the cache properly in a case of SQL-filtering. as a quick hack, you can just copy this function into your MyPage.php (not OtherPage.php) and comment out the first line.
i've added a ticket for this: http://open.silverstripe.com/ticket/1490 - should be fixed in the next major release.