After upgrading a site from j1.5 to j2.5.4 I have got problems hinding the main menu from the mobile site.
I have the main menu set up in location user3 (a Artisteer produced template for themain site).
But in Mobile Joomla there's no such module position so how comoe the menu still show?
For mobile menus I have position mj_smartphone_header.

The URL is: www.gagneffiske.se

So do you have two menus showing or just one on the mobile website? Have you assigned menu items to the template? If you did that could be an issue. Also, if you created a separate mobile menu, you will need to select that menu inside your mobile menu you have located in the mj_smartphone_header position.

Thanks for replying!
There are two menus showing on the mobile site but there should be only one, not the main menu from the regular site like it does now. I haven't assigned any menu items to the template.
I have created two separate mobile menus, one for smartphones and one for iphones.
What do you mean with the last sentence?

inside each of the menu modules you create, make sure you select the appropriate mobile menu. By default I believe the main menu is selected. 

If you have two menus, I suggest you to choose one menu for the selected phone into the main menu.

tlegens: Thank you this was all I needed to do!

But now the Main menu (the menu for the regular site) show up on all sub pages.....
This didn't happen before but now, why is that?
This happened when I upgraded to the latest 1.1.1 version of MJ.

If you need your menu for the mobile to be different than that of the main website, create another menu with all the items you need. Then assign that menu inside your mobile joomla menu module. Also, make sure you don't assign the menu items to any of the pages within the template parameters. Mobile Joomla will automatically know what template you are using based on device so no need to assign menu items within the template parameters.

tlegens: I hadn't assigned the correct menu to the module for the smartphone menu so thanks again for the tip.