Css Issue with London

For some reason the main menu on london gets some random arrows as soon as I add submenus, I've tried to change the CSS but it stays the same.

I added a screenshot in the attachements.
Hi Cristiano,

Do you see the same problem here: http://labs.outsystems.net/londontheme/ ?
What browser are you using?

Tiago Simões
No. Looks fine there.

I didnt do any changes in the London menu CSS though.