class names with and without opcache

On a default Ubuntu setup when writing 5.5 code I noticed an improvement with the resolution of class names such that an alias could be used even though a similar name already exists in the same namespace (B below). Namespace != Directory ? namespace B; use A\Test; But when 5.5 opcache is disabled, the code completely falls apart, stating that a class already exists with the same name even though that class is not actually used or referred to by the current script/file/class. There is a bug report https://bugs.php.net/bug.php?id=66773, but from the number of votes, I'm confused as to who and what is wrong - the conflicts occur when autoloading the two independent classes. The problem as I see it, even if I correct the aliases currently being used, if later on a class is created with the same name as an existing alias - then this new class will break code it has nothing to do with? I'm at the point of believing that all classes used within a script file should have a corresponding use statement to remove any ambiguity? Is this a bug? How severe is this? If I'm missing the point, please let me know.