IG: Unnecessary Thread Ctor..??

I get the following message:

Instiantiating a thread with a default run method.

When I use the following code:

DebugGUIBuilder buildIt = new DebugGUIBuilder(navProp,root);
Thread t = new Thread(buildIt);

DebugGUIBuilder implements runnable.

Am I doing something wrong? Should I create an IG bug?

Mike