Problem with menu position module

Question

I have a menu like this:

In the first sidebar you see the main menu with links.
The second sidebar is a block that is visible on pages that begin with stocklijst/.

The link in the first sidebar links to the first link in the second sidebar. So the menu items both have class active. But when I click on the second link in the second sidebar the menu link in the first sidebar won't be active anymore.

I've installed the Menu Position module to make sure the link is active but it doesn't work. I added a rule like this:

But the menu item isn't active when the path is equal to stocklijst/gezocht.

What am I doing wrong?

UPDATE:
This is my view:

Answer 1

From your comments, I came to know that you have added a new menu and used it as Menu Block in second sidebar region.

But Menu position module doesn't support new menus.

See the following points from Menu Position module page

This includes affecting:

• The main links of the theme

• The secondary links of the theme

• The breadcrumb trail

• Menu blocks provided by core's Menu module

• Menu blocks provided by the Menu Block module

So inorder to work with your new menu, you need to install Menu Block Module.

Menu Position module works well with Menu Block module.

So if you install Menu Block module you can use your custom menus also.

So… have you ever used the Main and Secondary menu links feature on your theme and wondered “how the hell do I display any menu items deeper than that?”

Well, that’s what this module does. It provides configurable blocks of menu trees starting with any level of any menu. And more!

I've tested this scenario and it works perfect.

Answer 2

For content with many individual entries - people, events, and articles - creating disabled menu items for each of them isn't practical. So we use a module called "menu position" to create fake disabled menu items for groups of content. Any content that matches the menu position rule (say - is an event) will "appear" to be in the menu where ever the menu position item is placed.

In the example above, all events will appear to be in the menu below Calendar. "Calendar" is the parent menu item of all events. This means that the event lists will display as options in the sub-menu on every individual event.

Menu position rules are created during site development, and content administrators cannot add new ones. However, if you remove the parent menu item, menu position rules will get really confused. If you see a menu item like the one above and are considering removing it's parent, talk to someone in Arts & Sciences Computing.