I too had this problem. Seems it is caused by “Device Code Highlighting.” This can be turned off with Window → Preferences → C/C++ → Editor → Syntax Coloring → Elements: Cuda C → Device Code Highlighting.
Enabled: [url]http://imgur.com/jh0KKvV[/url]
Disabled: [url]http://imgur.com/DE34Fbb[/url]