OK, confirmed ... but you should not be using the testing section ... testing is about "possibly unstable packages..."
Anyway, you need to downgrade dkms to version 2.0.19:
to do so open synaptic, select the package dkms
, then Synaptic Top menu -> Package -> Force version -> 2.0.19
, do the same for package dkms-minimal
when done, from a terminal run the following commands, other instructions will follow depending on the result:
rpm -qa | grep kernel