Tracking gaussian blur mask?

[Fin DePencier]

Hey guys, 

I'm trying to blur something here, and Premiere won't let me track the mask forward in the Gaussian blur effects control panel. The option to track it through the entire clip, or one frame at a time, is greyed out. What am I doing wrong here? See screenshot. 

Thanks in advance!

[R Neil Haugen]

I can't tell ... is the clip actually selected on the timeline?