title: IntelliJ IDEA "cannot resolve symbol" and "cannot resolve method"
body: <p>What are common causes for IntelliJ IDEA not being able to resolve built-in JVM types and methods? For example, when I mouse over <code>String</code> the tooltip says "Cannot resolve symbol 'String'". It's as if IntelliJ has doesn't know where the JVM is.</p>
  
  <p>By the way, I am running OS X 10.6.6. Everything was working fine until I ran the system update this morning.</p>