Hello Hornetville
One of my friends had a very similar problem the other day. I fixed her problem by repairing disk permissions. We can see if this works for you.
Go to your applications folder. Scroll down to the bottom and click on the utilities folder. Double click on Disk Utilities. On the left hand side of the window, select your Macintosh HD drive. Make sure the First Aid tab is selected as well. Now click on Repair Disk Permissions down at the bottom of the window. Once that's complete after about 20-30 minutes, restart your computer.
Let me know if this works. It worked for my friend.
Best of luck
Searay