Clutch clunk
 

I noticed today the with the engine running, parked in neutral, if I push in and release the clutch, it clunks when I let the pedal out. Only with the engine running and only when engaging the clutch. I found a post from about a year ago with the same noise, but no feed back on what the problem was or if it was fixed.
'08 base model that just turned 70k miles. I did have a rear wheel bearing replaced about a month ago, but I cannot see this as a factor.
Any ideas or is this a non problem. Seems to work fine.
Thanks in advance.

No ideas??