Duel Wielding question

Hi all,

I'm currently playing a duel-sword weilding barb using a combo of frenzy and bezerk.

The problem I'm having is getting a particular sword to become the primary weapon. I was using a flamberge(primary) and warsword(secondary for +2 skills) with no problems in setting my primary weapon.

The problem started with I wanted to swap out the flamberge with a rare Zweihander. No matter what order I equiped the Zweihander and warsword, the Zweihander would always be the secondary weapon.

Is this a "feature" related to certain sword classes or am I missing something obvious?

Thanks for your help.

Gotthund