Hi Kris, welcome aboard!
A couple of things.... Make sure you have the aircraft correctly loaded, with a zero load the Turbo Props tend to be very twitchy! Next when taxiing using a Turbo Prop, your Propellers should always be feathered to a near minimum setting to reduce the forward momentum (thrust) the props generate. You can do this from the throttle panel if I remember rightly. (Its been a long time since I flew the beech!) From what I have read on the SAAB forums, Taxiing is a very difficult task in the Turbo prop aircraft as it requires constant throttle adjustments to each engine individually.
Hope this helps.