libplasma2 and kdebase-workspace-data

Hi guys,
I'm trying to make a .deb package with cowdancer directly from a  
"debianized" source.
I got this error:

   libplasma2: Depends: kdebase-workspace-data (= 4:4.1.0-1) but it is not  
installable

packages.debian.org/libplasma2 reports dependency with  
kdebase-workspace-data 4.1.0-2 (I'm not on amd64).
packages.debian.org/kdebase-workspace-data reports 4.1.0-2 is good with  
all archs.

Now the question :)

I need to downgrade package kdebase-workspace-data from -2 to -1 to make  
compliant ? How I can selectively downgrade packages on cowdancer/pbuilder  
environment ?
I can ignore this warning ??? How I can force installation of a single  
package on cowdancer/pbuilder ?

10x a lot,
Salvatore