Updates to Counter-Strike: Source Beta have been released. The updates will be applied automatically when your Steam client is restarted. The specific changes include:

Counter-Strike: Source Beta

• Fixed prices not reverting to default when switching a server from blackmarket to regular
  
• Fixed some blackmarket buy menu elements showing up when not playing on a blackmarket server
  
• Fixed buy preset buttons not working under black market
  
• Removed warning about changing mp_dynamicprice while game is running

News Source: Steam News