The G530 in the Saab is the default unit from Laminar. I would try to enter the same data using a dafault Laminar airfcraft (Baron or King Air) and see if the same thing occurs. If it does, you may have a plugin conflict or it may be a bug in the 530. To test a plugin conflict remove all your plugins and retest. Put them back in one-by-one until the problem occurs again.