As far as I can tell they changed the VNE (Velocity Never Exceed) from 350Kts to 250Kts in either 11.30 RC1 or RC2. This means if you exceed about 240kts on autopilot, it will nose up to bleed off speed gaining altitude in the process. If this is your problem, you can fix it. Navigate to the Aircraft > Laminar Research > Cirrus SF-50 folder and open the file CirrusSF50.acf with a text editor. Search for an entry "P acf/_Vne_kts". If this is set to 250, change it to 350 and save. Hopefully this will fix your problem.