When you first turn your MacBook Pro on, does this issue occur while the Apple logo (on a grey background) appears, or only after you've logged in to your account?
When you first turn your MacBook Pro on, does this issue occur while the Apple logo (on a grey background) appears, or only after you've logged in to your account?
What happens if you create a new user account in System Preferences, log off of your current account, and then log on to the test account? Does the issue still occur in that scenario?
Are there any login items enabled for your normal account? You can find this by opening System Preferences and navigating to Accounts, select your user account, and then click on the Login Items tab.