2001 9-3 rear brake problem.

[RadoVR6]

I have an 01 9-3 Hot Aero and noticed the other day that one of the rear calipers is not working. i.e corrosion on the disc.

It looks like the caliper is siezed off. Is it likely to be a duff seal on the piston? I am changing the pads soon anyway so want to know what i might have to get ready when I sort it.

also do these have seperate drums for the handbrake?

Thanks