I called the Saab dealer in my city. They want to see the car with the radio. My problem is now I already scrapped my Saab but I use the saab radio on a Nissan car... Wish I don't have to put money in another radio.
Here's an old trick that might work, depending on the age of the unit. Take it out, disconnect all the wiring from the back, and - read this twice if you don't believe me - put in the freezer for a day or two*. Sometimes (an I mean sometimes) this will reset the machine. It sounds crazy, but I tried it on the head unit from my old Renault 5. I didn't think it would work, but it did. Put the head until back in the car, turned it on and it asked for the code. I just put in 0000 and it worked a treat, until some bugger broke into my car an stole it - Renault locks, I think, are made out of marshmallow and bits of string. If you've got the tools to take it out, give it a try... otherwise get a second hand until off ebay. You might even get my old one if it's back on the market!
*An after thought! Don't forget to put the head into a plastic bag and tie it up! If you put stright in, water vapour can creep inside and do bad things.