Xdebug in Eclipse getting confused between files of the same name

I have an Eclipse project (PHP) that has two different files named "ajax.inc".

When I set a breakpoint in one file (x/ajax.inc), the Eclipse debug mode opens the other file (y/ajax.inc).

This is more than a minor annoyance -开发者_如何学C every time I use the Step Over command, it pops me over to the editor window for the incorrect file.

Anyone know if there's some trick or configuration change that will keep this from happening, so that I can stay in the correct file while I'm debugging?