Had the issue on my 2003 and 2008. Now, the issue affected my current 2013 Corolla.
The lock would not go into valet (lockout) position. It also might hang up opening the trunk from valet lockout.
Tried silicone spray but only worked for a week or so. Went to Walmart and got a spray can of white silicone grease with a small plastic straw to get in tight spots. Put it inside the lock assembly, not the key cylinder.
Works great. Also used this lubricant for a light switch inside my fridge that stuck in the off mode. Another success.
