I’m getting compilation errors when I open a specific class file in Eclipse. However, the class doesn’t show a compilation error icon in the Project Explorer. I have enabled dependency management by right-clicking the project and using the Maven menu.
I’m using Eclipse 3.7.1 and Maven 2.2.1.

I’ve not seen this problem before, but I’d try performing the obligatory clean and build all on the project. I suggest making sure the following options are checked in Preferences -> Java -> Compiler -> Building:
There are several good suggestions in the question linked by
bdill, specifically to try updating your project configuration from the pom.