Cannot Find Symbol Class

I'm have a problem when IDEA (7821) makes my project.
I get Error: line (41,14) cannot find symbol class

However, when I go to that line and Click GoTo Declaration on the supposed missing class, IDEA finds it straight away.
Both the class with the error in and the supposed missing class are in the same package/directory.
Is make somehow using a different classpath to that used by the editors??