Clutch Slippage, or flat spot?

[CasiUSA]

Since I have no frame of refference for this, I figured I'd ask the experienced ones. When I pull the throttle open, every now and then, while in gear, somewhere around 7K RPMs, the bike seems to hit a dead spot. By this, I mean at around 7K RPMs, the engine seems to rev faster, but I don't feel the power of the bike pulling proportionately as hard. Is this a flat spot, or is my clutch slipping?
:dunno:
I have a stock main setup, and the larger pilot jets installed, with a 1 washer shim under the needle.

[mayz2010]

i think u'll find that that my friend is a flat spot

[octane]

A flat spot doesn't usually happen "every now and then". Sounds more to me like the clutch. Try adjusting the cable.